Electric force compounded grease and preparation method thereof

Abstract

The invention discloses electric force compounded grease and a preparation method thereof, and the electric force compounded grease is characterized by comprising the following components in parts by weight: 20-50 parts of fluorine-containing silicone oil, 70-110 parts of conductive filler and 16-34 parts of auxiliaries. The rain wash resistance of the electric force compounded grease is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power composite grease, and more specifically, to an electric power composite grease and a preparation method thereof. Background Art

[0002] Since high-voltage power transmission and transformation equipment is operated at high loads in the outdoor wilderness for a long time, as the voltage level increases, the quality of electrical contact at the connection of the power transmission and transformation equipment will directly determine the stability and reliability of the line and the quality of the current flow in the line, which is particularly important for the safe and stable operation of the power transmission and transformation equipment. The metal components of most power transmission and transformation equipment will bear a large load during operation. When affected by corrosive gases in the environment, electrochemical corrosion, inadequate maintenance and other factors, surface oxidation corrosion will occur at the contact end. Corrosion will form an oxide film between the contact surfaces, resulting in a reduction in contact area and an increase in contact resistance, which will cause a large amount of heat at the connection. In severe cases, it can burn or even burn the line, resulting in interruption of the connection of the power transmission and transformation equipment, causing large-scale power outages, and even fires and other major accidents. Therefore, it is urgent to solve the abnormal heating phenomenon of electrical contacts in power transmission and transformation equipment.

[0003] Therefore, in order to improve the quality of electrical connections and avoid heating and power loss in the electrical contact area, engineering usually applies power composite grease on the power transmission and distribution equipment to solve the problem. The power transmission and distribution lines are operated outdoors for a long time, and the power composite grease is inevitably affected by the external environment, especially long-term wind and rain erosion, which can easily cause the loss of power composite grease in the power contacts, thereby reducing the performance of the power composite grease. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art, provide a super-hydrophobic electric composite grease and a preparation method thereof, and reduce the loss of the electric composite grease caused by wind and rain erosion.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] An electric composite grease comprises the following components in parts by weight:

[0007] 20 to 50 parts of fluorine-containing silicone oil, 70 to 110 parts of conductive filler and 16 to 34 parts of auxiliary agent.

[0008] The present invention also provides a method for preparing the above-mentioned electric composite grease, comprising the following steps:

[0009] Grinding and mixing the conductive filler and the fluorine-containing silicone oil to obtain a mixed matrix;

[0010] The auxiliary agent is added into the mixed matrix, mixed and degassed to obtain the electric power composite grease.

[0011] Implementing the embodiments of the present invention will have the following beneficial effects:

[0012] The electric composite grease of the present invention can significantly improve the super hydrophobicity of the electric composite grease by using fluorinated silicone oil as the base grease, and reduce the loss of the electric composite grease caused by wind and rain erosion. In addition, compared with ordinary silicone oil, fluorinated silicone oil also has more excellent weather resistance, high and low temperature resistance, acid and alkali corrosion resistance and insulation performance, which can improve the weather resistance, high and low temperature resistance, acid and alkali corrosion resistance and insulation of the electric composite grease.

[0013] The electric composite grease of the present invention presents a uniform ointment in appearance as a whole, without obvious granular impurities, the product is fine, and the hardness and cone penetration indexes all meet the standards. It can be seen from the results that various detection performances are far superior to the standards. DETAILED DESCRIPTION

[0014] The following will be combined with 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.

[0015] The invention discloses an electric composite grease, comprising the following components in parts by weight:

[0016] 20 to 50 parts of fluorine-containing silicone oil, 70 to 110 parts of conductive filler and 16 to 34 parts of auxiliary agent.

[0017] In the above technical scheme, the fluorine-containing silicone oil is a modified silicone oil. The introduction of trifluoromethyl groups on the silicon atom can significantly improve the hydrophobicity of the silicone oil. The conductive filler is used to provide conductivity. The auxiliary agents include one or more of dispersants, thickeners, antioxidants and wear resistance agents.

[0018] In a specific embodiment, the fluorine-containing silicone oil includes one or more of vinyl fluorosilicone oil (CAS No.: 68951-98-4), hydroxy fluorosilicone oil (CAS No.: 63148-56-1), methyl fluoropropyl silicone oil (CAS No.: 63148-62-9) and perfluoroalkyl silicone oil (CAS No.: 83048-65-1).

[0019] Preferably, the fluorine-containing silicone oil includes vinyl fluorosilicone oil (CAS No.: 68951-98-4), hydroxy fluorosilicone oil (CAS No.: 63148-56-1), methyl fluoropropyl silicone oil (CAS No.: 63148-62-9) and perfluoroalkyl silicone oil (CAS No.: 83048-65-1), and the mixing mass ratio of vinyl fluorosilicone oil, hydroxy fluorosilicone oil, methyl fluoropropyl silicone oil and perfluoroalkyl silicone oil is 2-40:2-40:1-40:1-40, which can achieve a super hydrophobic contact angle of 160°±1° and show good stability for a long time.

[0020] In a specific embodiment, the conductive filler may include a metal conductive filler and a compound conductive filler.

[0021] Preferably, the conductive filler includes 60 to 80 parts by weight of a metal conductive filler and 10 to 30 parts by weight of a compound conductive filler, wherein the compound conductive filler includes a copper core, a silver coating layer covering the copper core, and a graphite coating layer covering the silver coating layer. The compound conductive filler can further improve the conductivity compared to the metal conductive filler. The technical solution uses a compound conductive filler and a metal conductive filler for compound use, which can provide higher conductivity with less conductive filler, and at the same time, reduce the use of metal conductive fillers and improve the corrosion resistance of the electric composite grease.

[0022] In the above technical solution, preferably, the thickness of the graphite coating layer is 30nm to 400nm, and the particle size of the composite conductive filler is 1000 mesh to 8000 mesh.

[0023] Further, in a preferred embodiment, the auxiliary agent includes the following components in parts by weight:

[0024] 2 to 4 parts of dispersant, 10 to 20 parts of thickener, 2 to 4 parts of antioxidant and 2 to 6 parts of anti-wear agent. The dispersant improves the uniformity of dispersion of various additives and conductive fillers in the fluorine-containing silicone oil. The thickener is used to adjust the cone penetration of the electric composite grease. The antioxidant is used to improve the oxidation resistance and stability of the electric composite grease. The anti-wear agent is used to improve the wear resistance of the electric composite grease.

[0025] Specifically, the dispersant may include one or more of polyethylene glycol, sodium polyacrylate, polyvinyl alcohol, and the like.

[0026] The thickener may include one or more of fumed silica, bentonite, polytetrafluoroethylene, and the like.

[0027] The antioxidant may include one or more of tert-tri(2,4-di-tert-butylphenyl)phosphite, tert-butylhydroxyanisole, dibutylhydroxytoluene, tert-butylhydroquinone, and the like.

[0028] The anti-wear agent may include one or more of aluminum oxide, silicon carbide, molybdenum disulfide, and the like.

[0029] The present invention also discloses a method for preparing the electric composite grease, comprising the following steps:

[0030] Step 1: Grind and mix the conductive filler and the fluorinated silicone oil to obtain a mixed matrix.

[0031] In a specific embodiment, the conductive filler and fluorinated silicone oil can be added into a three-roll mill, ground for 1 to 5 hours in a constant temperature environment of 60° C. to 80° C., and then allowed to stand for 5 to 10 minutes to prepare a mixed matrix.

[0032] In a specific embodiment, the conductive filler includes a metal conductive filler and a compound conductive filler, and the compound conductive filler includes a copper core, a silver coating layer coating the copper core, and a graphite coating layer coating the silver coating layer.

[0033] In a specific embodiment, the preparation method of the composite conductive filler comprises the following steps:

[0034] 1.1 Add ultrafine copper powder to the activation solution, stir and let it stand to separate the solid and liquid to obtain a copper powder suspension, then drop silver nitrate and tetraisopropyl di(dioctylphosphite) titanate complex mixture, add reducing agent disodium ethylenediaminetetraacetic acid, stir evenly, let it stand until the solid and liquid are separated, and vacuum dry to obtain dense silver-coated copper powder.

[0035] Specifically, the mixture can be stirred for 10 to 40 minutes at room temperature and then allowed to stand to separate the solid and liquid to obtain a copper powder suspension, to which a complex mixture of silver nitrate and tetraisopropyl di(dioctylphosphite) titanate is added dropwise in a constant temperature environment of 50°C to 100°C, and a reducing agent, disodium ethylenediaminetetraacetic acid, is added.

[0036] In a specific embodiment, the activation solution includes one or more of a suspension of 1,4-butynediol with a mass concentration of 2% and ammonium chloride with a mass concentration of 4%.

[0037] 1.2 The spherical modified graphite powder and the silver-coated copper powder obtained in step 1.1 are ground and mixed, and then added into a fusion coating machine for coating modification, and a graphite layer is coated on the surface of the silver-coated copper powder to prepare a composite conductive filler.

[0038] Specifically, the grinding and mixing time is 3h-6h; the coating and modification temperature is 100°C-220°C; and the coating and modification time is 5h-7h.

[0039] In this step, the spherical modified graphite powder and the spherical silver-coated copper powder are subjected to the high temperature and shear force generated by ball milling to realize the exfoliation of flake graphite to obtain thin-layer graphite with a thickness of 30-400nm and a particle size of 1000 mesh. The mechanical force shaping effect of ball milling is used to achieve the densest packing and surface activation of the composite powder. Coating fusion uses external mechanical force to completely embed one material in another material, combining them into a new material with the characteristics of two materials. Graphite is grafted onto the surface of copper powder to obtain a new material that has both the magnetic properties of metal materials and the ultra-high conductivity and toughness of graphite.

[0040] 1.3 Provide fluorinated silicone oil and metal conductive filler respectively.

[0041] In a specific embodiment, vinyl fluorosilicone oil (CAS No.: 68951-98-4), hydroxy fluorosilicone oil (CAS No.: 63148-56-1), methyl fluoropropyl silicone oil (CAS No.: 63148-62-9), and perfluoroalkyl silicone oil (CAS No.: 83048-65-1) are mixed in a mass ratio of 2:2:1:1 to obtain fluorine-containing silicone oil.

[0042] 1.4 Grind and mix the composite conductive filler prepared in step 1.2, the fluorinated silicone oil and the metal conductive filler prepared in step 1.3 to obtain a mixed matrix.

[0043] Step 2: Add the auxiliary agent to the mixed matrix obtained in step 1, mix and degas, and obtain the electric composite grease.

[0044] In a preferred embodiment, the various additives are first mixed, and then the mixed additives are added to the mixed matrix, mixed and degassed to prepare the finished product of the electric composite grease.

[0045] The following are specific embodiments.

[0046] Example 1

[0047] An electric composite grease comprises components in parts by weight as shown in Table 1.

[0048] Table 1: Component formula of the power compound grease of Example 1

[0049] Spherical graphite powder 12 servings Spherical silver coated copper powder 80 servings Sodium polyacrylate 4 servings Fumed Silica 8 servings Bentonite 10 servings Tris(2,4-di-tert-butylphenyl)phosphite 4 servings Molybdenum disulfide 4 servings Vinyl Fluorosilicone Oil 8 servings Hydroxyfluorosilicone oil 8 servings Methyl trifluoropropyl silicone oil 4 servings Methyl fluoropropyl silicone oil 4 servings

[0050] The specific preparation method is as follows:

[0051] (1) Ultrafine copper powder is added to an activation solution (a suspension of 1,4-butynediol with a mass concentration of 2% and ammonium chloride with a mass concentration of 4%), stirred at room temperature for 10 minutes and then allowed to stand to separate the solid and liquid to obtain a copper powder suspension, and a mixed solution of silver nitrate and tetraisopropyl di(dioctylphosphite) titanate complex is added dropwise in a constant temperature environment of 50°C, and a reducing agent, disodium ethylenediaminetetraacetic acid, is added, stirred evenly, allowed to stand until the solid and liquid are separated, and vacuum dried to obtain a dense silver-coated copper powder.

[0052] (2) Add spherical modified graphite powder of different sizes and the spherical silver-coated copper powder obtained in step (1) into a ball mill and grind for 2 hours to obtain 1000-mesh graphite powder and 2 μm fine copper powder, add the above-ground composite powder into a fusion coating machine, and use the mechanical force shaping effect of the ball mill to achieve the densest packing and surface activation of the composite powder, and carry out coating modification at a high temperature of 100-220° C. for 5-7 hours to obtain silver-coated copper powder with a thin layer of graphite coated on the surface, that is, a composite conductive filler.

[0053] (3) A mixture of fluorinated silicone oils (vinyl fluorosilicone oil, hydroxy fluorosilicone oil, methyl fluoropropyl silicone oil, and perfluoroalkyl silicone oil) was mixed in a mass ratio of 2:2:1:1 and stirred for 0.5 hours to allow the mixture to be fully mixed to obtain a base lipid solution.

[0054] (4) Sodium polyacrylate, fumed silica, bentonite, tri(2,4-di-tert-butylphenyl)phosphite, and molybdenum disulfide are added to a vacuum high shear dispersing and grinding device for grinding, homogenizing, and stirring for a total of 0.5 hours to prepare an auxiliary filler.

[0055] (5) Add the composite conductive filler prepared in step (2) and the base grease prepared in step (3) into a three-roll mill, grind for 1 hour in a constant temperature environment of 60 to 80° C., and let stand for 5 to 10 minutes to prepare a mixed matrix. Add the mixed additives into the mixed matrix at a uniform speed, stir evenly in a vacuum degasser for 0.5 hour, cool to room temperature, and finally prepare a finished product of electric composite grease.

[0056] Example 2

[0057] An electric composite grease comprises components in parts by weight as shown in Table 2.

[0058] Table 2: Component formula of the power compound grease of Example 2

[0059]

[0060]

[0061] The preparation method is the same as that in Example 1.

[0062] Example 3

[0063] An electric composite grease comprises components in parts by weight as shown in Table 3.

[0064] Table 3: Component formula of the power compound grease of Example 3

[0065] Spherical graphite powder 10 servings Spherical silver coated copper powder 60 servings Sodium polyacrylate 2 servings Fumed Silica 6 servings Bentonite 4 servings Tris(2,4-di-tert-butylphenyl)phosphite 2 servings Molybdenum disulfide 2 servings Vinyl Fluorosilicone Oil 6 servings Hydroxyfluorosilicone oil 6 servings Methyl trifluoropropyl silicone oil 4 servings Methyl fluoropropyl silicone oil 4 servings

[0066] The preparation method is the same as that in Example 1.

[0067] Comparative Example 1

[0068] The only difference between Comparative Example 1 and Example 1 is that the fluorine-containing silicone oil is replaced by ordinary silicone oil, and the formula is shown in Table 4.

[0069] Table 4: Component formula of the electric composite grease of Comparative Example 1

[0070]

[0071]

[0072] The preparation method is the same as that in Example 1.

[0073] Comparative Example 2

[0074] The only difference between Comparative Example 2 and Example 1 is that it lacks vinyl fluorosilicone oil, and the formula is shown in Table 5.

[0075] Table 5: Component formula of the power compound grease of Comparative Example 2

[0076] Spherical graphite powder 12 servings Spherical silver coated copper powder 80 servings Sodium polyacrylate 4 servings Fumed Silica 8 servings Bentonite 10 servings Tris(2,4-di-tert-butylphenyl)phosphite 4 servings Molybdenum disulfide 4 servings Hydroxyfluorosilicone oil 12 servings Methyl trifluoropropyl silicone oil 6 servings Methyl fluoropropyl silicone oil 6 servings

[0077] Comparative Example 3

[0078] The only difference between Comparative Example 3 and Example 1 is that hydroxy fluorosilicone oil is missing, and the formula is shown in Table 6.

[0079] Table 6: Component formula of the power compound grease of Comparative Example 3

[0080] Spherical graphite powder 12 servings Spherical silver coated copper powder 80 servings Sodium polyacrylate 4 servings Fumed Silica 8 servings Bentonite 10 servings Tris(2,4-di-tert-butylphenyl)phosphite 4 servings Molybdenum disulfide 4 servings Vinyl Fluorosilicone Oil 12 servings Methyl trifluoropropyl silicone oil 6 servings Methyl fluoropropyl silicone oil 6 servings

[0081] Comparative Example 4

[0082] The only difference between Comparative Example 4 and Example 1 is that methyl trifluoropropyl silicone oil is missing, and the formula is shown in Table 6.

[0083] Table 6: Component formula of the power compound grease of Comparative Example 5

[0084] Spherical graphite powder 12 servings Spherical silver coated copper powder 80 servings Sodium polyacrylate 4 servings Fumed Silica 8 servings Bentonite 10 servings Tris(2,4-di-tert-butylphenyl)phosphite 4 servings Molybdenum disulfide 4 servings Vinyl Fluorosilicone Oil 10 servings Hydroxyfluorosilicone oil 10 servings Methyl fluoropropyl silicone oil 4 servings

[0085] Comparative Example 5

[0086] The only difference between Comparative Example 5 and Example 1 is that methyl fluoropropyl silicone oil is missing, and the formula is shown in Table 7.

[0087] Table 7: Component formula of the power compound grease of Comparative Example 5

[0088] Spherical graphite powder 12 servings Spherical silver coated copper powder 80 servings Sodium polyacrylate 4 servings Fumed Silica 8 servings Bentonite 10 servings Tris(2,4-di-tert-butylphenyl)phosphite 4 servings Molybdenum disulfide 4 servings Vinyl Fluorosilicone Oil 10 servings Hydroxyfluorosilicone oil 10 servings Methyl trifluoropropyl silicone oil 4 servings

[0089] The test results of Examples 1 to 3 are shown in Table 8.

[0090] Table 8: Performance tests of Examples 1 to 3

[0091]

[0092]

[0093] The test results of Comparative Examples 1 to 5 are shown in Table 9.

[0094] Table 9: Performance test of comparative examples 1 to 5

[0095]

[0096]

[0097] The new type of electric composite grease made by the present invention presents a uniform ointment in appearance, without obvious granular impurities, the product is fine, and the hardness and cone penetration indicators meet the standards. The hydrophobic contact angle shows that the contact angle of water on the surface of the electric composite grease is as high as 160°±1°, and it shows good stability for a long time. Ultraviolet light shows that the surface of the paste is oily without fading, powdering, cracking, and embrittlement, and its pH value is neutral. It does not corrode the copper and aluminum sheets of the test samples, and has excellent corrosion resistance and anti-aging properties. Accelerated stability shows that the three products have no precipitation, stratification, and wall hanging. The dropping point of the product of the present invention is greater than 300°C, which breaks through the electric composite grease prepared by traditional single conductive filler and single silicone oil as the base grease. It not only utilizes the excellent conductivity of the coated metal powder, but also improves the corrosion resistance and rainwater scouring resistance of the electric composite grease by modifying the filler with a hydrophobic additive. It can be seen from the results that various detection performances are far superior to the standard. The preparation method of the electric composite grease is simple and low-cost, and can be mass-produced.

Claims

1. An electric composite grease, characterized in that: The composition comprises the following components in parts by weight: 20 to 50 parts of fluorine-containing silicone oil, 70 to 110 parts of conductive filler and 16 to 34 parts of auxiliary agent.

2. The electric composite grease according to claim 1, characterized in that: The fluorine-containing silicone oil includes one or more of vinyl fluorosilicone oil, hydroxy fluorosilicone oil, methyl fluoropropyl silicone oil and perfluoroalkyl silicone oil.

3. The electric composite grease according to claim 1, characterized in that: The fluorine-containing silicone oil includes vinyl fluorosilicone oil, hydroxy fluorosilicone oil, methyl fluoropropyl silicone oil and perfluoroalkyl silicone oil. The mixing mass ratio of the vinyl fluorosilicone oil, the hydroxy fluorosilicone oil, the methyl fluoropropyl silicone oil and the perfluoroalkyl silicone oil is 2-40:2-40:1-40:1-40.

4. The electric composite grease according to claim 1, characterized in that: The conductive filler includes a metal conductive filler and / or a compound conductive filler, and the compound conductive filler includes a copper core, a silver coating layer coating the copper core, and a graphite coating layer coating the silver coating layer.

5. The electric composite grease according to claim 4, characterized in that: The weight proportion of the metal conductive filler is 60 to 80 parts, and the weight proportion of the compound conductive filler is 10 to 30 parts.

6. The electric composite grease according to claim 4 or 5, characterized in that: The thickness of the graphite coating layer is 30nm-400nm, and the particle size of the composite conductive filler is 1000 mesh-8000 mesh.

7. The electric composite grease according to claim 1, characterized in that: The auxiliary agent includes one or more of a dispersant, a thickener, an antioxidant and an anti-wear agent.

8. The electric composite grease according to claim 1, characterized in that: The auxiliary agent comprises the following components in parts by weight: 2 to 4 parts of dispersant, 10 to 20 parts of thickener, 2 to 4 parts of antioxidant and 2 to 6 parts of anti-wear agent.

9. The electric composite grease according to claim 7 or 8, characterized in that: The dispersant includes one or more of polyethylene glycol, sodium polyacrylate and polyvinyl alcohol; The thickener includes one or more of fumed silica, bentonite and polytetrafluoroethylene; The antioxidant includes one or more of tert-tri(2,4-di-tert-butylphenyl)phosphite, butylated hydroxyanisole, butylated hydroxytoluene and tert-butylhydroquinone; The wear-resistant agent includes one or more of aluminum oxide, silicon carbide and molybdenum disulfide.

10. A method for preparing the electric composite grease according to any one of claims 1 to 9, characterized in that: The process includes: Grinding and mixing the conductive filler and the fluorine-containing silicone oil to obtain a mixed matrix; The auxiliary agent is added into the mixed matrix, mixed and degassed to obtain the electric power composite grease.

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