Calcium sulfonate lubricating grease and preparation method thereof

Abstract

The invention provides calcium sulfonate lubricating grease and a preparation method thereof, and belongs to the technical field of lubricating grease. The calcium sulfonate lubricating grease comprises the following raw material components in parts by mass: 35-45 parts of overbased calcium sulfonate; the lubricating oil is prepared from the following components in parts by weight: 25-35 parts of an organic solvent, 6-10 parts of water, 1.0-2.1 parts of small molecular acid, 1.1-2.1 parts of small molecular alcohol, 0.2-1.2 parts of a crystal form regulating agent and 35-65 parts of base oil. The preparation method comprises the following steps: (1) mixing the overbased calcium sulfonate and the organic solvent, then adding the crystal form regulating agent, after the crystal form regulating agent is dissolved, adding 3-5 parts of water in the raw material components, heating to 80-100 DEG C, and stirring to react for 1-2 hours; (2) mixing small-molecular acid, small-molecular alcohol and residual water, adding the mixture into the solution obtained in the step (1), stirring and reacting for 5 hours, and standing the reactant after the reaction is finished; and then adding the base oil, reacting and heating to 150-200 DEG C, stirring and reacting to dehydrate, evaporating to remove the solvent, thickening, and grinding to obtain the calcium sulfonate lubricating grease. The produced calcium sulfonate lubricating grease does not need to be subjected to a composite saponification reaction with fatty acid, the preparation process is simple, the high and low temperature performance is excellent, and the problems that existing lubricating grease is poor in colloid stability, high in thickening agent content and incapable of being used at low temperature can be effectively solved.

Description

Technical Field

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

[0002] Calcium sulfonate is often used as a detergent and rust inhibitor for lubricating oils. In the 1960s, researchers converted Newtonian calcium sulfonate into non-Newtonian calcium sulfonate and introduced calcium sulfonate high-base technology to produce high-base calcium sulfonate grease. Early calcium sulfonate greases had a high content of thickener, so the grease was very viscous, had poor low-temperature pumpability, and had a high production cost, which severely limited its widespread use. In the mid-1980s, people introduced fatty acids, boric acid and alkalis into the thickening process to improve the high and low temperature performance of greases. Although the comprehensive performance of the improved composite calcium sulfonate grease has surpassed other high-temperature greases in many aspects, it still has certain defects in colloidal stability, low-temperature pumpability and thickener content compared with composite lithium greases and polyurea greases.

[0003] The existing preparation process of composite calcium sulfonate grease mainly adopts a two-step method (patent publication numbers CN103740435A, CN1414076A, CN103740435A): first, Newtonian high-basic calcium sulfonate is converted into non-Newtonian high-basic calcium sulfonate under the action of a conversion agent, and then base oil, saponified acid and alkali are added to react to obtain composite calcium sulfonate grease. Alternatively, a one-step method (CN104450118A) is adopted to introduce CO2 into a mixed neutral calcium sulfonate, calcium oxide or calcium hydroxide, base oil, conversion agent and accelerator system until the carbonization process is completed to obtain non-Newtonian high-basic calcium sulfonate, and then base oil, saponified acid and alkali are added to react to obtain composite calcium sulfonate grease.

[0004] In patent EP2773589B1, Andrew et al. reduced the amount of high-base calcium sulfonate and increased the dropping point of calcium sulfonate grease by adding hydroxyapatite during the calcium sulfonate conversion reaction. In patent CN 104711080A, Fan et al. simultaneously added calcium hydroxide and lithium hydroxide to perform an integrated saponification reaction during the preparation of composite calcium sulfonate grease to improve the thickening ability of the grease. In patent CN 101993767A, Feng et al. improved the thermal stability and extreme pressure and anti-wear properties of composite calcium sulfonate grease by adding nano calcium carbonate to the grease formula.

[0005] In recent years, researchers' research on calcium sulfonate grease has mainly been based on complex soaps, with research conducted from two directions: improvement of thickening process and addition of additives. However, few people have paid attention to the morphology regulation of calcium sulfonate thickeners. Therefore, it is necessary to find new methods to prepare thickeners with different morphologies, and to explore the relationship between the microstructure and physical and chemical properties of calcium sulfonate grease based on the structure-activity relationship between thickener morphology and grease performance. Summary of the invention

[0006] In view of the above technical problems, the present invention provides a calcium sulfonate grease and a preparation method thereof, wherein the morphology of the calcium sulfonate thickener is first controlled by a crystal form regulator, thereby improving the colloidal stability and low temperature performance.

[0007] In order to achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A calcium sulfonate grease comprises the following raw material components in parts by weight: 35-45 parts of high base calcium sulfonate; 25-35 parts of organic solvent, 6-10 parts of water, 1.0-2.1 parts of small molecule acid, 1.1-2.1 parts of small molecule alcohol, 0.2-1.2 parts of crystal form regulator, and 35-65 parts of base oil.

[0009] The crystal form regulator is one or more of fatty acids, fatty amines or fatty alcohols with a carbon chain length of 8 to 20 carbons.

[0010] Preferably, the crystal form regulator is any one or more of dodecanoic acid, dodecylamine, octadecylamine and dodecanol.

[0011] The total base number of the overbased calcium sulfonate is 350-450 mgKOH / g.

[0012] The organic solvent is one or more of alkanes and cycloalkanes with less than 10 carbon atoms.

[0013] Preferably, the organic solvent is any one or more of petroleum ether, n-heptane and cyclohexane.

[0014] The small molecule acid is one or more of monobasic acids with less than 5 carbon atoms.

[0015] Preferably, the small molecule acid is any one or more of formic acid, acetic acid and propionic acid.

[0016] The small molecule alcohol is one or more of monohydric alcohols with less than 5 carbon atoms.

[0017] Preferably, the small molecule alcohol is any one or more of methanol, ethanol, propanol and butanol.

[0018] The base oil is one or more of mineral oil and / or synthetic oil.

[0019] Preferably, the base oil is of types 150BS and PAO40.

[0020] A method for preparing calcium sulfonate grease, comprising the following steps:

[0021] (1) mixing high base calcium sulfonate and an organic solvent, adding a crystal form regulator, and after the crystal form regulator is dissolved, adding 3-5 parts of water in the raw material components, heating to 80-100° C., and stirring to react for 1-2 hours;

[0022] (2) then adding a small molecule acid, a small molecule alcohol and the remaining water to the solution obtained in step (1), stirring the mixture for reaction for 1-10 hours, and allowing the mixture to stand after the reaction is completed;

[0023] (3) Then, the base oil is added, the reaction temperature is raised to 150-200°C, the reaction is stirred to dehydrate, the solvent is evaporated, and the mixture is thickened and ground to obtain calcium sulfonate grease.

[0024] Beneficial effects of the present invention: The present invention first reacts high-base calcium sulfonate with a crystal form regulator, and the prepared calcium sulfonate grease thickener has a large aspect ratio and specific surface area, and the morphology and size of the thickener have a great influence on the performance of the grease. Changing the morphology and size of the calcium carbonate thickener to a certain extent and increasing the specific surface area of ​​the thickener is conducive to increasing the content of adsorbed oil in the grease structure and increasing the dropping point of the grease. On the other hand, the larger aspect ratio of the thickener can increase the content of capillary oil in the grease, which reduces the percentage of the thickener content of the calcium sulfonate grease and increases the base oil content, thereby obtaining excellent low-temperature performance.

[0025] Therefore, the calcium sulfonate grease prepared by the present invention does not add any alkali, boric acid, dodecyl hydroxy stearic acid and other compounding agents, has a small amount of grease raw material composition, and a simple preparation method. The prepared calcium sulfonate has the characteristics of high dropping point (>260°C), strong thickening ability, low thickening agent content (<20%), excellent colloid stability, and excellent low temperature performance (similar viscosity <350). BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is a transmission electron microscope (TEM) image of the calcium sulfonate grease thickener prepared in Example 1.

[0028] Figure 2 This is the X-ray diffraction (XRD) pattern of the calcium sulfonate grease thickener prepared in Example 1. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0030] In the following examples and comparative examples, the parts are parts by weight, and the weight of each part is 1 g.

[0031] Example 1

[0032] A method for preparing calcium sulfonate grease, specifically comprising:

[0033] (1) Add 35 parts of high-base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 30 parts of n-heptane into a three-necked flask, then add 1.0 part of dodecanoic acid. After it is dissolved, add 5 parts of distilled water, heat to 80°C, and stir to react for 1 hour.

[0034] (2) Then, 1.0 part of formic acid, 1.5 parts of n-butanol and 5 parts of distilled water were mixed and added into a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0035] (3) Then, 60 parts of 150BS were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, and finally cooled to room temperature and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0036] The transmission electron microscope image of the prepared calcium sulfonate grease is shown in Figure 1 .Depend on Figure 1 It can be seen that the prepared calcium sulfonate grease is in the shape of a slender rod, about 35 nm long and about 7 nm wide.

[0037] The X-ray diffraction pattern of the prepared calcium sulfonate grease is shown in Figure 2 The diffraction peaks at 29.4°, 35.968°, 39.408°, 43.157°, 47.505°, and 48.503° in the figure are consistent with the standard card of calcium carbonate calcite crystal form (PDF#47-1743), corresponding to the characteristic diffraction crystal planes of calcite (104)(110)(113)(202)(018)(116), respectively. In addition, the diffraction peaks in the figure have obvious broadening phenomenon, which indicates that the slender rod-shaped calcium carbonate thickener has been successfully prepared.

[0038] Example 2

[0039] A method for preparing calcium sulfonate grease, specifically comprising:

[0040] (1) Add 40 parts of high base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 30 parts of petroleum ether into a three-necked flask, then add 1.0 part of octadecylamine. After it is dissolved, add 5 parts of distilled water, heat to 80°C, and stir to react for 1 hour.

[0041] (2) Then, 1.2 parts of formic acid, 1.5 parts of n-butanol, and 5 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0042] (3) Then, 60 parts of 150BS were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, and finally cooled to room temperature and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0043] Example 3

[0044] A method for preparing calcium sulfonate grease, specifically comprising:

[0045] (1) Add 35 parts of high-base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 35 parts of petroleum ether into a three-necked flask, then add 0.8 parts of dodecanol, wait for it to dissolve, add 4 parts of distilled water, heat to 90°C, and stir to react for 1 hour.

[0046] (2) Then, 1.5 parts of propionic acid, 1.7 parts of n-butanol, and 5 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0047] (3) Then, 4055 parts of PAO were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, cooled to room temperature, and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0048] Comparative Example 1

[0049] A method for preparing calcium sulfonate grease, specifically comprising:

[0050] (1) Add 35 parts of high-base calcium sulfonate and 40 parts of petroleum ether into a three-necked flask. After they are dissolved, add 6 parts of distilled water, heat to 90°C, and stir to react for 1 hour.

[0051] (2) Then, 0.7 parts of glacial acetic acid, 0.8 parts of ethanol, and 5 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0052] (3) Then, 40 parts of 150BS were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, and finally cooled to room temperature and ground three times with a three-roll mill to obtain calcium sulfonate grease. The performance indicators of the samples prepared in Examples 1-3 and Comparative Example 1 are shown in Table 1

[0053] Table 1

[0054]

[0055] It can be seen from Table 1 that after adding the crystal form regulator in the conversion step, the dropping point of the prepared calcium sulfonate grease is significantly increased compared with the comparative sample without adding the crystal form regulator. Figure 1 It can be seen from the transmission diagram that the addition of the crystal form regulator makes the calcium sulfonate grease thickener grow into a rod shape during the transformation process, and has a larger aspect ratio and specific surface area, so the adsorbed oil content in the grease structure increases, which improves the thickening ability and low temperature performance of the thickener, and at the same time improves the grease dropping point, and finally obtains a calcium sulfonate grease with both high and low temperature performance. In previous work (patent publication numbers CN103740435A, CN1414076A, CN103740435A), the improvement of the dropping point is often achieved by increasing the thickener content, but at the same consistency, Example 1 and Example 2 have both excellent low temperature performance and the highest dropping point, which is somewhat different from Example 3, which shows that the addition of the crystal form regulator not only regulates the thickener morphology, but also changes the interface characteristics of the thickener and the lubricating oil. The adsorption of organic acid and organic amine functional groups on the thickener surface is better than that of organic alcohols, so the physical and chemical properties of the prepared greases are quite different.

[0056] Example 4

[0057] A method for preparing calcium sulfonate grease, specifically comprising:

[0058] (1) Add 40 parts of high base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 25 parts of petroleum ether into a three-necked flask, then add 1.2 parts of octadecylamine. After it is dissolved, add 3 parts of distilled water, heat to 80°C, and stir to react for 1 hour.

[0059] (2) Then, 1.2 parts of formic acid, 1.5 parts of n-butanol, and 3 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0060] (3) Then, 65 parts of 150BS were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, cooled to room temperature, and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0061] Example 5

[0062] A method for preparing calcium sulfonate grease, specifically comprising:

[0063] (1) Add 45 parts of high-base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 25 parts of petroleum ether into a three-necked flask, then add 1.2 parts of octadecylamine. After it is dissolved, add 3 parts of distilled water, heat to 80°C, and stir to react for 1 hour.

[0064] (2) Then, 2.1 parts of formic acid, 2.1 parts of n-butanol, and 3 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0065] (3) Then, 35 parts of 150BS were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, cooled to room temperature, and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0066] Example 6

[0067] A method for preparing calcium sulfonate grease, specifically comprising:

[0068] (1) Add 40 parts of high-base calcium sulfonate (total base number ≥ 350 mgKOH / g) and 30 parts of petroleum ether into a three-necked flask, then add 0.2 parts of octadecylamine. After it is dissolved, add 5 parts of distilled water, heat to 80°C, and stir to react for 1 hour.

[0069] (2) Then, 2.1 parts of formic acid, 1.1 parts of n-butanol, and 3 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0070] (3) Then, 50 parts of 150BS were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, cooled to room temperature, and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0071] Example 7

[0072] A method for preparing calcium sulfonate grease, specifically comprising:

[0073] (1) Add 40 parts of high base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 25 parts of petroleum ether into a three-necked flask, then add 1.2 parts of octadecylamine. After it is dissolved, add 3 parts of distilled water, heat to 100°C, and stir to react for 1 hour.

[0074] (2) Then, 1.2 parts of formic acid, 1.5 parts of n-butanol, and 3 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 1 hour. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0075] (3) Then, 65 parts of 150BS were added, the reaction temperature was raised to 150°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, cooled to room temperature, and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0076] Example 8

[0077] A method for preparing calcium sulfonate grease, specifically comprising:

[0078] (1) Add 40 parts of high-base calcium sulfonate (total base number ≥ 350 mgKOH / g) and 30 parts of petroleum ether into a three-necked flask, then add 0.2 parts of octadecylamine. After it is dissolved, add 5 parts of distilled water, heat to 90°C, and stir to react for 2 hours.

[0079] (2) Then, 2.1 parts of formic acid, 1.1 parts of n-butanol, and 3 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 10 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0080] (3) Then, 50 parts of 150BS were added, the reaction temperature was raised to 200°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, cooled to room temperature, and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0081] Example 9

[0082] A method for preparing calcium sulfonate grease, specifically comprising:

[0083] (1) Add 40 parts of high base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 25 parts of n-heptane into a three-necked flask, then add 1.2 parts of dodecanoic acid. After it is dissolved, add 3 parts of distilled water, heat to 100°C, and stir to react for 1 hour.

[0084] (2) Then, 1.2 parts of acetic acid, 1.5 parts of methanol and 3 parts of distilled water were mixed and added into a three-necked flask, and stirred for reaction for 1 hour. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0085] (3) Then, 4065 parts of PAO were added, the reaction temperature was raised to 150°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, and finally cooled to room temperature and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0086] Example 10

[0087] A method for preparing calcium sulfonate grease, specifically comprising:

[0088] (1) Add 40 parts of high base calcium sulfonate (total base number ≥ 400 mgKOH / g) and 30 parts of cyclohexane into a three-necked flask, then add 1.0 part of dodecanol. After it is dissolved, add 5 parts of distilled water, heat to 80°C, and stir to react for 1 hour.

[0089] (2) Then, 1 part of propionic acid, 1 part of formic acid, 1.5 parts of propanol, and 5 parts of distilled water were mixed and added to a three-necked flask, and stirred for reaction for 5 hours. After the reaction was completed, the reactants in the flask were left to stand overnight.

[0090] (3) Then, 60 parts of 150BS were added, the reaction temperature was raised to 160°C, the reaction was stirred for dehydration, the solvent was evaporated, and the mixture was thickened. Finally, the mixture was kept at 200°C for 10 minutes, and finally cooled to room temperature and ground three times with a three-roll mill to obtain calcium sulfonate grease.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A calcium sulfonate grease, characterized in that: The invention comprises the following raw material components in parts by weight: 35-45 parts of high base calcium sulfonate; 25-35 parts of organic solvent; 6-10 parts of water; 1.0-2.1 parts of small molecule acid; 1.1-2.1 parts of small molecule alcohol; 0.2-1.2 parts of crystal form regulator; and 35-65 parts of base oil.

2. The calcium sulfonate grease according to claim 1, characterized in that The crystal form regulator is one or more of fatty acids, fatty amines or fatty alcohols with a carbon chain length of 8 to 20 carbons.

3. The calcium sulfonate grease according to claim 2, characterized in that: The crystal form regulator is any one or more of dodecanoic acid, dodecylamine, octadecylamine and dodecanol.

4. The calcium sulfonate grease according to any one of claims 1 to 3, characterized in that: The total base number of the overbased calcium sulfonate is 350-450 mgKOH / g.

5. The calcium sulfonate grease according to claim 4, characterized in that The organic solvent is one or more of alkanes and cycloalkanes with less than 10 carbon atoms, preferably petroleum ether, n-heptane and cyclohexane.

6. The calcium sulfonate grease according to claim 5, characterized in that The small molecule acid is one or more of monobasic acids with less than 5 carbon atoms, preferably formic acid, acetic acid, propionic acid, etc.

7. The calcium sulfonate grease according to claim 5 or 6, characterized in that: The small molecule alcohol is one or more of monohydric alcohols with less than 5 carbon atoms.

8. The calcium sulfonate grease according to claim 7, characterized in that The base oil is one or more of mineral oil and / or synthetic oil.

9. The method for preparing the calcium sulfonate grease according to any one of claims 1 to 8, characterized in that: Preparation steps: (1) mixing high base calcium sulfonate and an organic solvent, adding a crystal form regulator, and after the crystal form regulator is dissolved, adding 3-5 parts of water in the raw material components, and heating for reaction; (2) then adding a small molecule acid, a small molecule alcohol and the remaining water to the solution obtained in step (1), and continuing the reaction for 1-10 hours. After the reaction is completed, the reactants are allowed to stand; (3) Then, the base oil is added, the reaction temperature is raised to 150-200°C, the reaction is stirred to dehydrate, the solvent is evaporated, and the mixture is thickened and ground to obtain calcium sulfonate grease.

10. The method for preparing calcium sulfonate grease according to claim 9, characterized in that: The heating reaction temperature in step (1) is 80-100° C. and the time is 1-2 h.

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