A sunroof slide rail lubricating grease composition with excellent low temperature performance and a method for producing the same

Abstract

The present application relates to the technical field of lubricating grease, and particularly relates to a sunroof sliding rail lubricating grease composition with excellent low-temperature performance and a preparation method thereof.The composition comprises base oil and thickening agent;the mass ratio of the base oil to the thickening agent is (7-9):(1-2);the base oil is composed of synthetic oil and silicone oil;the mass ratio of the synthetic oil to the silicone oil is (0.5-5):1;the thickening agent is obtained by the reaction of fatty acid and lithium hydroxide;the mass ratio of the fatty acid to the lithium hydroxide is (10-20):(1-3).The present application provides a lubricating grease composition with excellent low-temperature performance based on a specific base oil system and thickening agent.The lubricating grease composition provided by the present application also has excellent rust and corrosion resistance, colloid stability, water resistance and oxidation resistance, and has a long service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lubricating grease, in particular to a sunroof sliding rail lubricating grease composition with excellent low-temperature performance and a preparation method thereof. BACKGROUND

[0002] Automobile sunroof has the functions of ventilation and support, which can not only improve the driving environment, but also ensure the quality of the automobile. The automobile sunroof sliding rail is the main structural component of the automobile sunroof, and the performance of the product directly affects the service life and driving comfort of the automobile sunroof.

[0003] Automobile sunroof lubricating grease is a kind of lubricating grease specially used for automobile sunroof system. It is mainly used for lubricating sunroof sliding rail, roller, guide rail and other movable parts to ensure smooth opening and closing operation and prevent noise and friction. Traditional automobile sunroof sliding rail lubricating grease is mostly butter on the market, which cannot meet the use requirements at low temperature.

[0004] There are also different researches in the prior art to provide lubricating grease for automobile sunroof sliding rail. For example, the patent with application number 201510490269.7 discloses a lubricating grease for automobile sunroof sliding rail, which uses polyolefin as base oil, composite lithium-calcium as thickening agent, and adds anti-oxidation additives, metal passivator, anti-rust and anti-corrosion agent, multi-effect additive, polyolefin, etc. to obtain a lubricating grease with high and low temperature resistance, water resistance and corrosion resistance. Similar to this patent, the lubricating grease in the prior art mostly uses polyolefin as base oil and adopts composite lithium-calcium as thickening agent, because polyolefin and composite lithium-calcium themselves have excellent low-temperature properties, and have excellent flowability and volatility resistance under low-temperature conditions. However, for the lubricating grease used for automobile sunroof sliding rail, there is still room for further improvement in its low-temperature performance. SUMMARY

[0005] In order to solve the problems existing in the prior art, the present application provides a sunroof sliding rail lubricating grease composition with excellent low-temperature performance and a preparation method thereof.

[0006] The prior art mostly uses polyolefin as base oil and composite lithium-calcium as thickening agent, because polyolefin and composite lithium-calcium have good low-temperature properties, and the grease prepared therefrom can maintain certain fluidity and lubricating performance under low-temperature conditions. For example, the patent document with the application number 201510490269.7 discloses that the starting torque at -40℃ can reach 0.370 N·m at the lowest, and the running torque can reach 0.104 N·m at the lowest. However, the low-temperature performance of this kind of grease used for automobile sunroof sliding rails still has room for further improvement. The inventors have accidentally found a combination of base oil and thickening agent in the research process, in which synthetic oil and silicone oil are used as base oil, the molecular chain is stable and the molecular arrangement is neat, the low-temperature viscosity is small, the viscosity-temperature performance is good, and the oil film can be quickly formed, so that the grease has more excellent low-temperature performance. In addition, there are various interactions between the thickening agent and the base oil, and the 12-hydroxystearic acid and stearic acid compounded as the thickening agent molecules can form hydrogen bonds with the hydroxyl groups in the molecules, which is more conducive to hindering the coordination of peroxide molecules at the hydroxyl groups, so that the carbon chain of the base oil molecule is tightly wound, and the base oil is not easy to be oxidized and deteriorated. In addition, the low-temperature starting torque and running torque are reduced due to the good lubricity of the thickening agent molecules themselves.

[0007] In a first aspect, the present application provides a grease composition, comprising: base oil and thickening agent;

[0008] The mass ratio of the base oil to the thickening agent is (7-9):(1-2);

[0009] The base oil is composed of synthetic oil and silicone oil; the mass ratio of the synthetic oil to the silicone oil is (0.5-5):1;

[0010] The thickening agent is obtained by the reaction of fatty acid and lithium hydroxide; the mass ratio of the fatty acid to the lithium hydroxide is (10-20):(1-3).

[0011] Further, the synthetic oil comprises poly-alpha olefin and / or synthetic ester oil; and / or, the silicone oil comprises one or more of methyl silicone oil, methylene silicone oil and toluene-based silicone oil.

[0012] Further, the poly-alpha olefin has a kinematic viscosity of 10-50 mm 2 / s at 40℃ and a viscosity index of 140-160; and / or, the synthetic ester oil has a kinematic viscosity of 20-40 mm 2 / s at 40℃ and a viscosity index of 140-150; and / or, the silicone oil has a kinematic viscosity of 300-1000 mm 2 / s at 25℃.

[0013] Further, the fatty acid comprises one or more of 12-hydroxystearic acid, stearic acid, oleic acid or E acid. Preferably consists of 12-hydroxystearic acid and stearic acid.

[0014] Further, it also comprises one or more of solid filler, high molecular polymer, antioxidant, anti-rust agent or extreme pressure anti-wear agent.

[0015] Further, the grease composition comprises, in parts by weight:

[0016] Base oil 70-90 parts, thickening agent 10-20 parts, solid filler 5-20 parts, high molecular polymer 0.5-2 parts, antioxidant 1-5 parts, anti-rust agent 1-5 parts and extreme pressure anti-wear agent 1-5 parts.

[0017] Further, the high molecular polymer is a synthetic high molecular compound or a natural high molecular compound.

[0018] Further, the molecular weight of the high molecular polymer is 200-20000, which has good thermal stability, oxidation stability and shear resistance.

[0019] The high molecular polymer added in the present application can make the grease have higher adhesion and longer service life.

[0020] Further, the antioxidant comprises amine antioxidant and / or phenolic antioxidant; and / or,

[0021] The extreme pressure anti-wear agent comprises one or more of organic sulfide, organic phosphide or organic metal salt; and / or,

[0022] The anti-rust agent comprises one or more of organic carboxylic acid, organic carboxylic acid salt, ester or organic amine anti-rust agent; and / or,

[0023] The solid filler is a powdery solid inorganic substance.

[0024] Further, the amine antioxidant comprises one or more of diphenylamine, diisooctyl diphenylamine, beta-naphthylamine, alkylated diphenylamine or p-phenylenediamine; and the phenolic antioxidant is selected from one or both of 2,6-di-tert-butyl-p-cresol and beta-naphthol. It is found that the amine antioxidant and the phenolic antioxidant can produce a synergistic effect, can completely capture the free radicals generated by the base oil and form stable groups, hinder the oxidation of the base oil, inhibit the oxidation of the fatty acid carbon chain and glycerol, and passivate the catalytic effect of the metal, thus having excellent high-temperature antioxidant effect.

[0025] Further, the extreme pressure anti-wear agent comprises one or more of sulfurized isobutylene, triphenyl phosphorothionate and trimethyl phosphorite cresol. The present application finds that the above extreme pressure anti-wear agents produce synergistic effect, and the sulfur-containing additives can be adsorbed on the surface of the friction pair, and react with the metal to form a dense oxide film as the temperature rises, thereby improving the load capacity of the grease, and the phosphorus-containing additives have high anti-wear capacity, thus having more excellent extreme pressure performance and anti-wear performance.

[0026] Further, the anti-rust agent comprises calcium dinonylnaphthalene sulfonate and / or zinc naphthenate.

[0027] As a preferred embodiment, the present application provides a grease composition comprising, by weight:

[0028] synthetic oil 55-60 parts, silicon oil 15-30 parts, thickening agent 10-15 parts, phenolic antioxidant 1-1.5 parts, high molecular polymer 1-1.5 parts, extreme pressure anti-wear agent 1.5-2.5 parts, anti-rust agent 1-1.5 parts and solid filler 10-12 parts.

[0029] In a second aspect, the present application provides a preparation method of the grease composition, comprising:

[0030] saponifying the first part of base oil with lithium hydroxide, fatty acid and high molecular polymer to obtain a first material;

[0031] heating the first material to about 130-150℃, adding the second part of base oil to obtain a second material;

[0032] heating the second material to 200-215℃, mixing with the third part of base oil, and rapidly cooling to 150-180℃ to obtain a third material; adding antioxidant when the temperature drops to 110-130℃ to obtain a fourth material; cooling to 50-80℃, and mixing the fourth material with anti-rust agent, extreme pressure anti-wear agent and solid filler.

[0033] In a third aspect, the present application provides the use of the grease composition or the grease composition prepared by the preparation method in automobile sunroof system grease, preferably sunroof rail grease.

[0034] The present application has the following advantages:

[0035] The present application provides a grease composition based on synthetic oil and silicone oil as base oil components, in which case the use of a thickening agent using the reaction product of a fatty acid and lithium hydroxide can significantly improve the low temperature performance of the grease, making it have lower starting torque and running torque under low temperature conditions, and enabling it to be used in complex external environments such as rain and snow, ultra-low temperature, and have a long service life. In addition, the grease provided by the present application also has better adhesion and water resistance, and can cope with extreme conditions such as salt water corrosion; at the same time, it has excellent colloidal stability, wear resistance and oxidation resistance. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0037] Figure 1 is a comparison diagram of the low temperature performance of the greases of each example and the comparative example provided by Test Example 1 of the present application under the condition of -40°C. DETAILED DESCRIPTION

[0038] The following embodiments further illustrate the present application, and the following embodiments are illustrative and not limiting, and the protection scope of the present application cannot be limited by the following embodiments. If not specifically indicated, the technical means used in the embodiments is the conventional means familiar to those skilled in the art. In the embodiments, each raw material added is a conventional raw material on the market, unless otherwise specified.

[0039] In the following examples and comparative examples, the synthetic oil is selected from poly-alpha olefin or synthetic ester oil, the poly-alpha olefin has a kinematic viscosity of 10-50 mm 2 / s at 40°C and a viscosity index of 140-160; the synthetic ester oil has a kinematic viscosity of 20-40 mm 2 / s at 40°C and a viscosity index of 140-150.

[0040] The silicone oil has a kinematic viscosity of 300-1000 mm 2 / s at 25°C, and is selected from methyl silicone oil, methylene silicone oil and toluene silicone oil.

[0041] Example 1

[0042] The present embodiment provides a grease composition, and the preparation method thereof comprises:

[0043] Into the reaction kettle, 500 g of PAO oil was added, and 75 g of 12-hydroxystearic acid, 75 g of stearic acid, and 21 g of lithium hydroxide were added for saponification reaction. The reaction time was 1 h. After saponification was completed, the temperature was raised to 130-140°C, 200 g of PAO oil was added, and the temperature was raised to 200°C. Then, 350 g of methylene silicone oil was added, and the temperature after quenching was controlled at 170-180°C. When the temperature dropped to 120°C, 18 g of 2,6-di-tert-butyl-p-cresol was added, and when the temperature dropped to 50°C, 18 g of triphenyl phosphorothioate, 12 g of calcium dinonylnaphthalene sulfonate, and 120 g of polytetrafluoroethylene were added. After being uniformly dispersed by a three-roll mill, thickening and canning were performed.

[0044] Example 2

[0045] The present embodiment provides a grease composition, and a method for preparing the same, the method comprising:

[0046] Into the reaction kettle, 500 g of PAO oil was added, and 100 g of 12-hydroxystearic acid, 50 g of stearic acid, and 24 g of lithium hydroxide were added for saponification reaction. The reaction time was 1 h. After saponification was completed, the temperature was raised to 130-140°C, 200 g of methyl silicone oil was added, and the temperature was raised to 200°C. Then, 350 g of synthetic ester oil was added, and the temperature after quenching was controlled at 170-180°C. When the temperature dropped to 120°C, 18 g of diphenylamine was added, and when the temperature dropped to 50°C, 18 g of triphenyl phosphorothioate, 12 g of calcium dinonylnaphthalene sulfonate, and 120 g of polytetrafluoroethylene were added. After being uniformly dispersed by a three-roll mill, thickening and canning were performed.

[0047] Example 3

[0048] The present embodiment provides a grease composition, and a method for preparing the same, the method comprising:

[0049] Into the reaction kettle, 500 g of PAO oil was added, and 100 g of 12-hydroxystearic acid, 50 g of stearic acid, and 24 g of lithium hydroxide were added for saponification reaction. The reaction time was 1 h. After saponification was completed, the temperature was raised to 130-140°C, 200 g of methyl silicone oil was added, and the temperature was raised to 200°C. Then, 350 g of synthetic ester oil was added, and the temperature after quenching was controlled at 170-180°C. When the temperature dropped to 120°C, 18 g of diphenylamine was added, and when the temperature dropped to 50°C, 18 g of triphenyl phosphorothioate, 12 g of calcium dinonylnaphthalene sulfonate, and 120 g of polytetrafluoroethylene were added. After being uniformly dispersed by a three-roll mill, thickening and canning were performed.

[0050] Example 4

[0051] The present embodiment provides a grease composition, and a method for preparing the same, the method comprising:

[0052] Into a reaction kettle, 500 g of PAO oil was added, and 100 g of 12-hydroxystearic acid, 40 g of stearic acid, 5 g of oleic acid, 5 g of E acid, 21 g of lithium hydroxide, and 12 g of natural rubber were added to perform a saponification reaction. The reaction time was 1 h. After the saponification was completed, the temperature was increased to 130-140°C, 200 g of PAO oil was added, and the temperature was increased to 200°C. Then, 350 g of methyl silicone oil was added. The temperature after the quenching was controlled to be 170-180°C. When the temperature was decreased to 120°C, 18 g of alkylated diphenylamine was added. When the temperature was decreased to 50°C, 18 g of triphenyl phosphorothionate, 12 g of calcium dinonylnaphthalene sulfonate, and 120 g of cyanuric acid melamine were added. After the mixture was uniformly dispersed by a three-roll mill, the mixture was thickened and canned.

[0053] Example 5

[0054] The present example provides a lubricating grease composition, and a method for preparing the same, which comprises:

[0055] Into a reaction kettle, 700 g of PAO oil was added, and 150 g of 12-hydroxystearic acid and 21 g of lithium hydroxide, and 12 g of natural rubber were added to perform a saponification reaction. The reaction time was 1 h. After the saponification was completed, the temperature was increased to 130-140°C, 200 g of benzyl silicone oil was added, and the temperature was increased to 200°C. Then, 150 g of benzyl silicone oil was added. The temperature after the quenching was controlled to be 170-180°C. When the temperature was decreased to 120°C, 18 g of alkylated diphenylamine was added. When the temperature was decreased to 50°C, 18 g of triphenyl phosphorothionate, 12 g of calcium dinonylnaphthalene sulfonate, and 120 g of cyanuric acid melamine were added. After the mixture was uniformly dispersed by a three-roll mill, the mixture was thickened and canned.

[0056] Example 6

[0057] The present example provides a lubricating grease composition, and a method for preparing the same, which comprises:

[0058] Into a reaction kettle, 500 g of PAO oil was added, and 150 g of 12-hydroxystearic acid and 21 g of lithium hydroxide, and 12 g of ethylene propylene copolymer were added to perform a saponification reaction. The reaction time was 1 h. After the saponification was completed, the temperature was increased to 130-140°C, 200 g of -PAO oil was added, and the temperature was increased to 200°C. Then, 350 g of methylene silicone oil was added. The temperature after the quenching was controlled to be 170-180°C. When the temperature was decreased to 120°C, 18 g of diphenylamine was added. When the temperature was decreased to 50°C, 18 g of triphenyl phosphorothionate, 12 g of calcium dinonylnaphthalene sulfonate, and 120 g of polytetrafluoroethylene were added. After the mixture was uniformly dispersed by a three-roll mill, the mixture was thickened and canned.

[0059] Comparative Example 1

[0060] The lubricating grease composition provided in the present comparative example is different from that of Example 1 only in that the base oil of the present comparative example comprises 500 g of PAO oil, 350 g of silicone oil, and 200 g of polyether.

[0061] The preparation method of the grease composition of the present comparative example comprises:

[0062] Into the reaction kettle, 500 g of PAO oil was added, and 150 g of 12-hydroxystearic acid, 21 g of lithium hydroxide, 3 g of calcium hydroxide, and 12 g of G1702 were put in for saponification reaction, the reaction time was 1 h, after the saponification was completed, the temperature was raised to 130-140°C, 200 g of polyether was added, and when the temperature rose to 200°C, 350 g of methyl silicone oil was added, the temperature after quenching was controlled at 170-180°C, when the temperature dropped to 120°C, 18 g of 2, 6-di-tert-butyl-p-cresol was added, when the temperature dropped to 50°C, 18 g of triphenyl phosphorothionate was added, 12 g of calcium dinonylnaphthalene sulfonate, 120 g of polytetrafluoroethylene was added, and after being uniformly dispersed by a three-roll mill, the thickening tank was filled.

[0063] Comparative Example 2

[0064] The grease composition provided by the present comparative example is only different from Example 1 in that the base oil system is different. The specific process is as follows:

[0065] Into the reaction kettle, 500 g of PAO oil was added, and 75 g of 12-hydroxystearic acid, 75 g of stearic acid, 21 g of lithium hydroxide, 3 g of calcium hydroxide, and 12 g of G1702 were put in for saponification reaction, the reaction time was 1 h, after the saponification was completed, the temperature was raised to 130-140°C, 200 g of PAO oil was added, and when the temperature rose to 200°C, 350 g of PAO oil was added, the temperature after quenching was controlled at 170-180°C, when the temperature dropped to 120°C, 18 g of 2, 6-di-tert-butyl-p-cresol was added, when the temperature dropped to 50°C, 18 g of triphenyl phosphorothionate was added, 12 g of calcium dinonylnaphthalene sulfonate, 120 g of polytetrafluoroethylene was added, and after being uniformly dispersed by a three-roll mill, the thickening tank was filled.

[0066] Comparative Example 3

[0067] The grease composition provided by the present comparative example is only different from Example 1 in that the thickening agent system is different. The specific process is as follows:

[0068] Into the reaction kettle, 500 g of PAO oil was added, and 150 g of 12-hydroxystearic acid, 21 g of lithium hydroxide, 3 g of calcium hydroxide, and 12 g of G1702 were put in for saponification reaction, the reaction time was 1 h, after the saponification was completed, the temperature was raised to 130-140°C, 200 g of PAO oil was added, and when the temperature rose to 200°C, 350 g of methyl silicone oil was added, the temperature after quenching was controlled at 170-180°C, when the temperature dropped to 120°C, 18 g of 2, 6-di-tert-butyl-p-cresol was added, when the temperature dropped to 50°C, 18 g of triphenyl phosphorothionate was added, 12 g of calcium dinonylnaphthalene sulfonate, 120 g of polytetrafluoroethylene was added, and after being uniformly dispersed by a three-roll mill, the thickening tank was filled.

[0069] Test Example 1

[0070] The performances of the grease compositions provided by the examples and the comparative examples of the present application were tested, and the results are shown in Table 1.

[0071] Table 1 Comparison of grease performances of the examples and the comparative examples

[0072]

[0073]

[0074] As shown in Table 1, the low temperature starting torque and running torque of the grease compositions prepared by the examples 1-6 of the present application at -40℃ are smaller than those of the comparative examples 1-3, and the oil separation amount of the grease under the simulated working condition is also small, which all show good low temperature fluidity and colloidal stability, etc., indicating that the use of a certain proportion of synthetic oil and silicone oil as the base oil and the use of lithium soaps of two kinds of fatty acid compounds as the thickening agent are more in line with the requirements and working conditions of the sunroof rail grease; the grease has excellent oxidation stability and is not easy to oxidize at high temperature, which ensures that the surface is not hardened, so that the sunroof can run normally and stably in different regions and different temperature environments; the grease has excellent shear resistance, which ensures that the fiber structure of the grease is not easily damaged; the grease has excellent water resistance, which ensures that the sunroof grease is not eroded by rainwater, etc., and the service life is greatly prolonged. Among them, the grease composition provided by example 1 has the best comprehensive performance.

[0075] Figure 1 For the low temperature efficiency test results (under the conditions of 50N, 100N, 150N and 200N) of the examples and the comparative examples, it can be seen from Table 2 that Figure 1 that the grease compositions prepared by the examples 1-6 of the present application have the best low temperature efficiency at -40℃, which ensures that the grease meets the use requirements in complex external environments such as rain, snow, ultra-low temperature and dust, and has a long service life. Among them, the grease composition provided by example 1 has the best low temperature efficiency.

[0076] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for part of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the examples of the present application.

Claims

1. A grease composition characterized in that, The grease composition comprises, by weight, 70-90 parts of base oil, 10-20 parts of thickening agent, 5-20 parts of solid filler, 0.5-2 parts of high molecular polymer, 1-5 parts of antioxidant, 1-5 parts of anti-rust agent and 1-5 parts of extreme pressure anti-wear agent; The base oil is composed of synthetic oil and silicone oil; the mass ratio of the synthetic oil to the silicone oil is (0.5-5):1; the synthetic oil comprises one or more of poly-alpha olefin, synthetic ester oil; the silicone oil comprises one or more of methyl silicone oil, methylene silicone oil or toluene-based silicone oil; The thickening agent is obtained by the reaction of fatty acid and lithium hydroxide; the mass ratio of the fatty acid to the lithium hydroxide is (10-20):(1-3); the fatty acid is composed of 12-hydroxystearic acid and stearic acid; The high molecular polymer is selected from one of G1702, ethylene propylene copolymer or natural rubber; The solid filler is polytetrafluoroethylene.

2. The grease composition according to claim 1, characterized in that, said poly-alpha olefin has a kinematic viscosity at 40°C of 10 to 50 mm 2 / s, a viscosity index of 140 to 160; and / or, said synthetic ester oil has a kinematic viscosity at 40°C of 20 to 40 mm 2 / s; a viscosity index of 140 to 150; and / or, said silicone oil has a kinematic viscosity at 25°C of 300 to 1000 mm 2 / s.

3. The grease composition of claim 1, wherein The antioxidant comprises amine antioxidant and / or phenolic antioxidant; and / or, The extreme pressure anti-wear agent comprises one or more of organic sulfide, organic phosphide or organic metal salt; and / or, The anti-rust agent comprises one or more of organic carboxylic acid, organic carboxylic acid salt, ester or organic amine anti-rust agent.

4. Process for the preparation of the grease composition according to any one of claims 1 to 3, characterized in that, The method comprises: saponifying the first part of base oil, lithium hydroxide, fatty acid and high molecular polymer to obtain a first material; heating the first material to 130-150 DEG C, adding the second part of base oil to obtain a second material; heating the second material to 200-215 DEG C, mixing with the third part of base oil, rapidly cooling to 150-180 DEG C, then mixing with the remaining base oil, and cooling to 50-80 DEG C to obtain a third material; mixing the third material with antioxidant, anti-rust agent, extreme pressure anti-wear agent and solid filler.

5. The use of the grease composition of any one of claims 1-3 or the grease composition prepared by the method of claim 4 as automobile sunroof system grease.

6. Use according to claim 5, characterized in that, The grease composition has a running torque of 0.045 N·m at -40 DEG C.

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