Anhydrous calcium-based grease and its preparation method and application

Abstract

The present invention belongs to the technical field of petroleum products, and specifically relates to an anhydrous calcium-based lubricating grease and a preparation method and application thereof. The present invention provides an anhydrous calcium-based lubricating grease, comprising a thickener, a lubricant, an antioxidant, an inorganic filler, and a rust inhibitor, wherein the lubricant comprises a poly-alpha-olefin synthetic oil and a synthetic ester base oil. The anhydrous calcium-based lubricating grease provided by the present invention is not only low in cost and has good compatibility with the sealing ring of the automobile sunroof, but also has good lubricity and water resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum products, and in particular relates to an anhydrous calcium-based lubricating grease and a preparation method and application thereof. Background Art

[0002] The maintenance process of the car sunroof is generally divided into two aspects: one is the cleaning of the rubber strip, and the other is the cleaning of the drain pipe and the lubrication of the slide rail. Since ordinary grease is easy to condense dust after a long time of use, causing the sunroof to stagnate, it is easy to block the drainage hole and cause water leakage. At the same time, the grease must be very compatible with the sunroof sealing ring, otherwise the sealing ring will gradually age during use, causing poor sealing and causing water leakage in the sunroof. Therefore, the car sunroof slide rail needs to be sealed and lubricated with special grease.

[0003] At present, the lubricating grease for the sliding rail of the automobile sunroof is generally a semi-solid lithium-based lubricating grease. However, due to the price of lithium hydroxide, the cost of the lubricating grease is high, which is not conducive to industrial use. In the research of the prior art, there are attempts to replace lithium hydroxide with calcium hydroxide, which is cheaper. For example, Chinese patent CN109797032A discloses a new type of anhydrous calcium-based lubricating grease and a preparation method, which uses calcium hydroxide as a thickener. However, this grease has poor compatibility with the sealing ring of the sunroof, resulting in poor sealing performance after a period of use, causing water leakage in the sunroof. Summary of the invention

[0004] The purpose of the present invention is to provide an anhydrous calcium-based grease and a preparation method and application thereof. The anhydrous calcium-based grease provided by the present invention has good compatibility with the sealing ring of the automobile sunroof and low cost; it also has good waterproofness after long-term use, and can maintain stability, sealing and lubricity in high or low temperature environments.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides an anhydrous calcium-based lubricating grease, comprising the following components in percentage by weight: 7-9% thickener, 68-72% lubricant, 0.3-0.5% antioxidant, 20-24% inorganic filler, and 0.3-0.5% rust inhibitor;

[0007] The lubricant includes polyalphaolefin synthetic oil and synthetic ester base oil;

[0008] The thickener is obtained by saponifying mixed fatty acids and calcium hydroxide.

[0009] Preferably, the mass ratio of the mixed fatty acid to calcium hydroxide is 10:1 to 8:2.

[0010] Preferably, the mixed fatty acid includes 12-hydroxystearic acid and stearic acid, and the mass ratio of 12-hydroxystearic acid to stearic acid is 8:2 to 6:4.

[0011] Preferably, the mass ratio of the poly-alpha-olefin synthetic oil to the synthetic ester base oil is 1:0.2 to 1:0.3.

[0012] Preferably, the rust inhibitor comprises tolyltriazole.

[0013] Preferably, the antioxidant includes one or more of diphenylamine, methyldiphenylamine, phenyl-α-naphthylamine and 2,6-di-tert-butyl-p-cresol.

[0014] Preferably, the inorganic filler is calcium carbonate, the particle size of the calcium carbonate is 10-15 μm, and the density of the calcium carbonate is 2.6-2.7 g / cm 2 .

[0015] The present invention provides a method for preparing the anhydrous calcium-based grease described in the above technical solution, comprising the following steps:

[0016] (1) mixing part of the lubricant, the mixed fatty acid and the calcium hydroxide to carry out a saponification reaction to obtain a saponified material;

[0017] (2) heating and dehydrating the saponified material, mixing the obtained dehydrated material and the remaining lubricant and homogenizing them to obtain a homogeneous material;

[0018] (3) The homogeneous material, antioxidant, inorganic filler and rust inhibitor are mixed to obtain the anhydrous calcium-based grease.

[0019] Preferably, the saponification reaction temperature is 100-105° C., and the insulation time is 1-2 hours.

[0020] The present invention provides the use of the anhydrous calcium-based lubricating grease described in the above technical solution or the anhydrous calcium-based lubricating grease prepared by the preparation method described in the above technical solution as a lubricating oil for automobile sunroof slide rails.

[0021] The anhydrous calcium-based grease provided by the present invention comprises the following components in percentage by weight: 7-9% thickener, 68-72% lubricant, 0.3-0.5% antioxidant, 20-24% inorganic filler, and 0.3-0.5% rust inhibitor; the lubricant comprises polyalphaolefin synthetic oil and synthetic ester base oil; the thickener is obtained by saponification of mixed fatty acid and calcium hydroxide. The thickener of the present invention cooperates with the lubricant, is dispersed in the lubricant and forms the structural skeleton of the grease, so that the lubricant is adsorbed and fixed in the structural skeleton, and the thickener of the present invention is obtained by saponification of mixed fatty acid and calcium hydroxide, and the raw material cost is low, which effectively saves the cost. In addition, the present invention effectively enhances the compatibility of the product with synthetic rubber by using the mixed use of polyalphaolefin synthetic oil and synthetic ester base oil. At the same time, the antioxidant, inorganic filler, rust inhibitor, etc. of the present invention have the characteristics of good water resistance, and assist the thickener and lubricant to prepare a heavy and compact anhydrous calcium-based grease. It can be seen from the examples that the anhydrous calcium-based grease prepared in the present application is not only low in cost and has good compatibility with the sealing ring of the automobile sunroof, but also has good lubricity and water resistance.

[0022] The present invention provides a method for preparing the anhydrous calcium-based grease described in the above technical solution, comprising the following steps: (1) mixing part of the lubricant, mixed fatty acid and calcium hydroxide for saponification reaction to obtain a saponified material; (2) heating and dehydrating the saponified material, and homogenizing the obtained dehydrated material and the remaining lubricant to obtain a homogenous material; (3) mixing the homogenous material, an antioxidant, an inorganic filler and a rust inhibitor to obtain the anhydrous calcium-based grease. The preparation method of the present application improves the saponification effect of the reaction by adding the lubricant in steps, and the addition of antioxidants, inorganic fillers and rust inhibitors can improve the water resistance of the anhydrous calcium-based grease. Therefore, the anhydrous calcium-based grease prepared by the present invention can be used on automobile sunroof slide rails. DETAILED DESCRIPTION

[0023] The present invention provides an anhydrous calcium-based lubricating grease, comprising the following components in percentage by weight: 7-9% thickener, 68-72% lubricant, 0.3-0.5% antioxidant, 20-24% inorganic filler, and 0.3-0.5% rust inhibitor;

[0024] The lubricant includes polyalphaolefin synthetic oil and synthetic ester base oil;

[0025] The thickener is obtained by saponifying mixed fatty acids and calcium hydroxide.

[0026] In the present invention, unless otherwise specified, the required raw materials for preparation are all commercially available products well known to those skilled in the art.

[0027] Calculated by mass percentage, the anhydrous calcium-based grease provided by the present invention includes 7-9% of thickener, preferably 7.5-8.5%.

[0028] In the present invention, the thickener is obtained by saponification of mixed fatty acids and calcium hydroxide. The mixed fatty acid preferably includes 12-hydroxystearic acid and stearic acid, and the mass ratio of 12-hydroxystearic acid to stearic acid is preferably 8:2 to 6:4, more preferably 6:2 to 6:3; the mass ratio of the mixed fatty acid to calcium hydroxide is preferably 10:1 to 8:2, more preferably 9:1 to 9:2.

[0029] In the present invention, 12-hydroxystearic acid and stearic acid are respectively saponified with calcium hydroxide, and the obtained thickener can thicken lubricating oil to prepare calcium-based grease.

[0030] Calculated by mass percentage, the anhydrous calcium-based grease provided by the present invention comprises 70-75% of lubricant, preferably 71.5-74%.

[0031] In the present invention, the lubricant comprises polyalphaolefin synthetic oil (PAO) and synthetic ester base oil, the mass ratio of the polyalphaolefin synthetic oil to the synthetic ester base oil is preferably 1:0.2 to 1:0.3, more preferably 1:0.25; the polyalphaolefin synthetic oil is preferably PAO 20, the viscosity at 100°C is preferably 20cst, the pour point is preferably less than -40°C, and the viscosity index is preferably greater than 130. In the present invention, the kinematic viscosity of PAO 20 changes little due to temperature changes. In the present invention, the synthetic ester base oil is preferably trimellitate, and specifically trimellitate 1941 is preferably preferred.

[0032] Since polyalphaolefin synthetic oil has a certain shrinkage effect on rubber, the present invention can effectively enhance the compatibility of the product with synthetic rubber by mixing polyalphaolefin synthetic oil and synthetic ester base oil and adjusting the mass ratio of polyalphaolefin synthetic oil to the synthetic ester base oil to preferably be 1:0.2 to 1:0.3.

[0033] Calculated by mass percentage, the anhydrous calcium-based grease provided by the present invention includes 0.3-0.5% of antioxidant, preferably 0.35-0.4%.

[0034] In the present invention, the antioxidant preferably includes one or more of diphenylamine, methyldiphenylamine, phenyl-α-naphthylamine and 2,6-di-tert-butyl-p-cresol, more preferably one of diphenylamine and methyldiphenylamine, and further preferably methyldiphenylamine.

[0035] Calculated by mass percentage, the anhydrous calcium-based grease provided by the present invention comprises 20-25% of inorganic filler, preferably 21-24%.

[0036] In the present invention, the inorganic filler is preferably calcium carbonate, the particle size of the calcium carbonate is preferably 10 to 15 μm, more preferably 12 to 14 μm; the density of the calcium carbonate is preferably 2.6 to 2.7 g / cm 2 .

[0037] The present invention adds calcium carbonate as an inorganic filler, which not only has a wear-resistant effect, but also serves as a water-resistant filler, has chemical stability and water resistance, can improve the water resistance, sealing and wear resistance of the grease, and is conducive to the use of the grease on the automobile sunroof slide rail.

[0038] Calculated by mass percentage, the anhydrous calcium-based grease provided by the present invention includes 0.3-0.5% of rust inhibitor, preferably 0.35-0.4%.

[0039] In the present invention, the rust inhibitor is preferably methylbenzotriazole The methylbenzotriazole It has good anti-rust function for non-ferrous metals and can improve the anti-rust effect of grease.

[0040] The present invention provides a method for preparing the anhydrous calcium-based grease described in the above technical solution, comprising the following steps:

[0041] (1) mixing part of the lubricant, the mixed fatty acid and the calcium hydroxide to carry out a saponification reaction to obtain a saponified material;

[0042] (2) heating and dehydrating the saponified material, mixing the obtained dehydrated material and the remaining lubricant and homogenizing them to obtain a homogeneous material;

[0043] (3) The homogeneous material, antioxidant, inorganic filler and rust inhibitor are mixed to obtain the anhydrous calcium-based grease.

[0044] The present invention mixes part of lubricant, mixed fatty acid and calcium hydroxide to carry out saponification reaction to obtain saponified material.

[0045] In the present invention, the mass of the partial lubricant preferably accounts for 1 / 3 to 1 / 2 of the total mass of the lubricant, and more preferably 1 / 2.

[0046] In the present invention, the mixing preferably comprises the following steps: heating part of the lubricant and the mixed fatty acid until they are dissolved to obtain a mixed liquid; and mixing the mixed liquid with calcium hydroxide. In the present invention, the heating temperature is preferably 80°C.

[0047] In the present invention, the saponification reaction temperature is preferably 100-105°C; the holding time is preferably 1-2 hours, more preferably 2 hours. The saponification reaction is preferably carried out under stirring conditions, and the present invention has no special requirements for the specific implementation process of the stirring.

[0048] The present invention can improve the saponification effect of the reaction by adding the lubricant in steps. The present invention uses raw materials for preparing thickeners, mixed fatty acids and calcium hydroxide and part of the lubricant raw materials for saponification reaction, which can make the lubricant better adsorbed in the skeleton structure of the thickener.

[0049] After obtaining the saponified material, the present invention heats the saponified material for dehydration, and the obtained dehydrated material is mixed with the remaining lubricant and then homogenized to obtain a homogenous material.

[0050] In the present invention, the heat preservation temperature of the heating dehydration is preferably 140° C., and the heat preservation time is preferably 10 minutes. In the present invention, the dehydrated material is alkaline.

[0051] In the present invention, the homogenization is preferably carried out in a homogenizer, the insulation temperature of the homogenization is preferably 100-120°C, and the homogenization pressure is preferably 150 kg / cm 2 The heat preservation and pressure holding time of the homogenization is preferably 2 hours. In the present invention, the homogenization is carried out under stirring.

[0052] After obtaining the homogeneous material, the present invention mixes the homogeneous material, an antioxidant, an inorganic filler and a rust inhibitor to obtain the anhydrous calcium-based grease.

[0053] In the present invention, the mixing is preferably carried out under stirring. The order of mixing the homogeneous material, antioxidant, inorganic filler and rust inhibitor is preferably: premixing the homogeneous material and the inorganic filler under a first temperature condition to obtain a premix; cooling the premix to a second temperature and mixing with the antioxidant and the rust inhibitor. In the present invention, the first temperature is preferably 100-120°C. The second temperature is preferably ≤90°C.

[0054] In the present invention, the homogeneous material, antioxidant, inorganic filler and rust inhibitor are mixed to obtain an initial grease, and the present invention preferably further comprises vacuum degassing the initial grease to obtain an anhydrous calcium-based grease. In the present invention, the vacuum degree of the vacuum degassing is preferably 600-800 mmHg. The present invention preferably packages the anhydrous calcium-based grease after passing the inspection.

[0055] The anhydrous calcium-based lubricating grease provided by the present invention has a specific gravity greater than 1 through a certain proportion. Since the greater the specific gravity of the same substance, the greater the density, the better the relative sealing performance. The specific gravity of general lubricating grease is about 0.8 to 0.86, and the sealing performance is slightly poor. The product of the present invention has more precise sealing performance. At the same time, the formula provided by the present invention adopts a mixture of polyalphaolefin synthetic oil and synthetic ester base oil, which effectively enhances the compatibility of the product with synthetic rubber. Therefore, the product of the present invention has good lubricity, high and low temperature resistance, and water resistance. In addition, the anhydrous calcium-based grease type automobile sunroof slide rail grease produced by the technology of the present invention has low cost, is not affected by the high price of lithium hydroxide raw materials of lithium-based grease, and is not affected by large fluctuations. Compared with lithium-based grease products, the cost is reduced.

[0056] The present invention provides the use of the anhydrous calcium-based lubricating grease described in the above technical solution or the anhydrous calcium-based lubricating grease prepared by the preparation method described in the above technical solution as a lubricating oil for automobile sunroof slide rails.

[0057] The anhydrous calcium-based grease provided by the present invention can be directly used on the sliding rails of automobile sunroofs. It is resistant to high and low temperatures during use, and the temperature range of use is preferably -40 to 120°C. It also has the characteristics of good compatibility with synthetic rubber. During the compatibility test with synthetic rubber, the weight increase is less than 1% after 168 hours at 70°C, which is only half of the weight increase of the anhydrous calcium-based grease prepared using only PAO oil, indicating that the anhydrous calcium-based grease provided by the present invention has good compatibility with synthetic rubber.

[0058] In order to further illustrate the present invention, the anhydrous calcium-based grease provided by the present invention and its preparation method and application are described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0059] Example 1

[0060] According to the raw materials and proportions of Example 1 in Table 1, the following components were weighed in percentage by mass: 6.3% 12-hydroxystearic acid, 2.7% stearic acid, 1.7% calcium hydroxide, 54.4% PAO 20, 144% trimellitate, 20% calcium carbonate, 0.5% methyl diphenylamine, 0.5% methyl benzotriazole, 0.6% methyl benzoate, 0.7% methyl benzoate, 0.8% methyl benzoate, 0.9% methyl benzoate, 0.9% methyl benzoate, 0.1% methyl benzoate, 0.2% methyl benzoate, 0.3% methyl benzoate, 0.4% methyl benzoate, 0.5% methyl benzoate, 0.6% methyl benzoate, 0.7% methyl benzoate, 0.8% methyl benzoate, 0.9% methyl benzoate, 0.8% methyl benzoate, 0.9% methyl benzoate, 0.4%;

[0061] Heat up 12-hydroxystearic acid, stearic acid and 1 / 2 of the base oil to dissolve completely. When the temperature is 80°C, start adding calcium hydroxide and stir for saponification for 2 hours. Control the temperature at 100°C for saponification for 2 hours. After the saponification is completed, slowly heat up for dehydration until the temperature reaches 140°C, maintain for 10 minutes, and gradually add the remaining base oil. At the same time, take a sample and titrate it with phenolphthalein. The color is red and alkaline. After the base oil is added, pour the kettle and cool it with a homogenizer at a temperature of 110°C and a pressure of 150kg / cm 2 , homogenize for 2h, then add calcium carbonate solid powder, stir evenly until 90℃, then add methylbenzene and methyl diphenylamine, stir evenly, then degas under vacuum degree of 600-800mmHg, and can be packaged after passing the inspection.

[0062] Example 2

[0063] The preparation process is the same as that of Example 1. The types and mass percentages of the raw materials used in Example 2 are listed in Table 1.

[0064] Example 3

[0065] The preparation process is the same as that of Example 1. The types and mass percentages of the raw materials used in Example 3 are listed in Table 1.

[0066] Comparative Example 1

[0067] The preparation process is the same as that of Example 1. The types and mass percentages of the raw materials used in Comparative Example 1 are listed in Table 1.

[0068] Comparative Example 2

[0069] The preparation process is the same as that of Example 1. The types and mass percentages of the raw materials used in Comparative Example 2 are listed in Table 1.

[0070] Table 1 Types and mass percentages of raw materials used in Examples 1 to 3 and Comparative Examples 1 to 2

[0071]

[0072] Table 2 Test results of Examples 1 to 3 and Comparative Examples 1 to 2

[0073]

[0074] Table 2 shows the test results of dropping point, oxidation stability, compatibility with synthetic rubber, etc. of Examples 1 to 3 and Comparative Examples 1 to 2. According to the test results of Comparative Example 1, it can be seen that the compatibility of the anhydrous calcium-based grease mixed with PAO oil and trimellitate with synthetic rubber is better than the compatibility of the anhydrous calcium-based grease with synthetic rubber using only PAO oil. According to the test results of Comparative Example 2, it can be seen that the oxidation stability, steel mesh oil separation, and dropping point of the anhydrous calcium-based grease with added calcium carbonate are better than those of the anhydrous calcium-based grease without added calcium carbonate.

[0075] The anhydrous calcium-based automobile sunroof slide rail grease provided by the present invention is not only low in cost, being 70-75% of the original lithium-based grease, but also has good compatibility with the sealing ring of the automobile sunroof and good lubricity, sealing and water resistance, and meets the use specification requirements of the sunroof slide rails in the automobile industry.

[0076] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An anhydrous calcium-based grease, characterized in that: It is composed of the following components in percentage by mass: Thickener 7~9%, lubricant 68~72%, antioxidant 0.3~0.5%, inorganic filler 20~24%, rust inhibitor 0.3~0.5%; The lubricant is a polyalphaolefin synthetic oil and a synthetic ester base oil; the polyalphaolefin synthetic oil is PAO 20, and the synthetic ester base oil is trimellitate; the mass ratio of the polyalphaolefin synthetic oil to the synthetic ester base oil is 1:0.2 to 1:0.3; The thickener is obtained by saponification of mixed fatty acids and calcium hydroxide; The inorganic filler is calcium carbonate; The anhydrous calcium-based lubricating grease is used to improve compatibility with the sealing ring of the automobile sunroof.

2. The anhydrous calcium-based grease according to claim 1, characterized in that: The mass ratio of the mixed fatty acid to calcium hydroxide is 10:1-8:

2.

3. The anhydrous calcium-based grease according to claim 1 or 2, characterized in that: The mixed fatty acid comprises 12-hydroxystearic acid and stearic acid, and the mass ratio of the 12-hydroxystearic acid to stearic acid is 8:2-6:

4.

4. The anhydrous calcium-based grease according to claim 1, characterized in that: The rust inhibitor includes tolyltriazole.

5. The anhydrous calcium-based grease according to claim 1, characterized in that: The antioxidant includes one or more of diphenylamine, methyl diphenylamine, phenyl-α-naphthylamine and 2,6-di-tert-butyl-p-cresol.

6. The anhydrous calcium-based grease according to claim 1, characterized in that: The particle size of the calcium carbonate is 10-15 μm, and the density of the calcium carbonate is 2.6-2.7 g / cm 2 .

7. The method for preparing anhydrous calcium-based grease according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) mixing part of the lubricant, the mixed fatty acid and the calcium hydroxide to carry out a saponification reaction to obtain a saponified material; (2) heating and dehydrating the saponified material, mixing the obtained dehydrated material and the remaining lubricant and homogenizing them to obtain a homogeneous material; (3) The homogeneous material, antioxidant, inorganic filler and rust inhibitor are mixed to obtain the anhydrous calcium-based grease.

8. The preparation method according to claim 7, characterized in that: The temperature of the saponification reaction is 100-105° C., and the insulation time is 1-2 hours.

9. Use of the anhydrous calcium-based lubricating grease according to any one of claims 1 to 6 or the anhydrous calcium-based lubricating grease obtained by the preparation method according to claim 7 or 8 as a lubricating oil for automobile sunroof slide rails.

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