Amide conductive lubricating grease with low friction and low contact resistance

Abstract

Amide conductive lubricating grease with low friction and low contact resistance belongs to the technical field of conductive lubricating grease, the conductive lubricating grease comprises basic conductive lubricating grease and composite conductive lubricating grease, the basic conductive lubricating grease is formed by mixing base oil and a thickening agent, and the composite conductive lubricating grease is formed by mixing base oil, a thickening agent and an additive; the thickening agent is synthesized by carrying out amidation reaction on fatty acids and amines according to a certain proportion. The fatty acid selected by the thickening agent is a natural compound, naturally exists in animal and plant grease and is free of environmental pollution, and the composite conductive lubricating grease prepared on the basis of the fatty acid has no corrosion to a friction pair under an application working condition. The basic conductive lubricating grease and the composite conductive lubricating grease prepared by the invention can keep low friction coefficient and low contact resistance under a current-carrying condition, and have relatively good load change resistance, current change resistance and frequency change resistance. The preparation method is simple, low in cost and beneficial to large-scale production.

Description

Technical Field

[0001] The invention belongs to the technical field of conductive grease, and in particular relates to amide conductive grease with low friction and low contact resistance. Background Art

[0002] In the moving parts through which the current passes, the wear state of the friction pair determines whether the current can be transmitted normally. When the current passes through the conductive part of the electrical contact friction pair, the arc generated at the contact interface makes the friction pair susceptible to arc erosion and wear. The wear of electrical contacts is affected by many factors such as force and electricity. It is limited by mechanical factors and affected by current and arc erosion.

[0003] In order to solve the problems of electrical contact, friction and wear, conductive lubricants are usually used at the friction interface to ensure the normal operation of the friction pair. Conductive lubricants are of great significance for reducing friction and wear during electrical contact, extending service life, and promoting the intelligent and efficient development of power electronic equipment. Conductive lubricants are mainly divided into conductive lubricating oils and conductive greases. Conductive greases are widely used due to their good adhesion and non-flowing properties. Conductive greases are based on synthetic oils, mineral oils, etc., and after thickening with a thickener, various types of additives (conductive materials, antioxidant materials, anti-corrosion materials, arc suppression materials, etc.) are added as required to obtain a semi-solid lubricating material.

[0004] However, the dispersibility of conductive additives and the like in grease is poor, resulting in poor lubrication effect. At present, conductive grease is often treated by homogenization methods such as modification, uniform dispersion and grinding. Chinese patent CN105296116A discloses an environmentally friendly castor-based conductive grease, comprising 12-hydroxystearate lithium soap and antioxidants, friction modifiers, anti-wear agents, rust inhibitors, conductive agents, adhesives, etc. In addition, the conductive lubricating additive has a weak binding force in the base conductive grease and is dispersed therein in a free state, making it difficult to form a stable and firm conductive grease system. Chinese patent CN116640262B discloses an acidifying thickener and a synthesis method thereof, using a thickening acid containing sulfonic acid as a conductive grease thickener, which has the disadvantages of being prone to environmental pollution, which seriously restricts development.

[0005] In summary, the problems existing in the prior art are: the current preparation method of conductive grease is relatively complicated, and the conductive performance of the prepared conductive grease is poor and unstable. The additives such as anti-friction and anti-wear additives, rust removers, conductive additives, adhesives, etc. mixed in the conductive grease are poorly dispersed in the base grease, the synthesis cost is high, and long-term contact friction is corrosive to the friction pair, damages the friction pair, and easily pollutes the environment. Summary of the invention

[0006] The invention discloses amide conductive lubricating grease with low friction and low contact resistance, aiming to solve the problems existing in the prior art.

[0007] To achieve the above purpose, the technical solution of the present invention is:

[0008] An amide conductive grease with low friction and low contact resistance, the conductive grease comprises a basic conductive grease and a composite conductive grease, the basic conductive grease is formed by mixing a base oil and a thickener, the composite conductive grease is formed by mixing a base oil, a thickener and additives; the thickener is synthesized by amidation reaction of fatty acids and amines in a certain proportion.

[0009] Preferably, the molar ratio of the fatty acids to the amines is 3:1.

[0010] Preferably, the base oil is one or more of polyalphaolefin, liquid paraffin, alkylated aromatic hydrocarbon and perfluoropolyether.

[0011] Preferably, the fatty acid is one or more of oleic acid, ricinoleic acid, linoleic acid and linolenic acid.

[0012] Preferably, the amine is one or more of melamine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine.

[0013] Preferably, the additive includes one or more of hydroxylated carbon nanotubes (MWCNTs-OH), graphene, reduced graphene oxide (r-GO), fullerene, metal particles, and carbon black.

[0014] Preferably, the metal particles include one or more of copper powder, silver powder, molybdenum disulfide, and tungsten disulfide.

[0015] Preferably, the mass proportion of the additive is 1%-10% of the total mass of the composite conductive grease.

[0016] Preferably, the mass proportion of the thickener is 20%-60% of the total mass of the basic conductive grease.

[0017] The beneficial effects of the amide conductive grease with low friction and low contact resistance of the present invention are:

[0018] 1. The fatty acid selected as the thickener of the present invention is a natural compound, which exists naturally in the oils and fats of animals and plants and has no pollution to the environment. The composite conductive grease prepared based on the fatty acid is not corrosive to the friction pair under the application conditions.

[0019] 2. The basic conductive grease and composite conductive grease prepared by the present invention can maintain a low friction coefficient and a low contact resistance under current-carrying conditions, and have good resistance to load changes, current changes, and frequency changes.

[0020] 3. The preparation method of the present invention is simple, low-cost, and is conducive to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 , physical pictures of the basic conductive grease and composite conductive grease provided by the present invention.

[0022] Figure 2 , friction coefficient and contact resistance of composite conductive grease. DETAILED DESCRIPTION

[0023] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0024] The following embodiments may be understood as individually expressing a part of a local structure or method of the present invention, or may be understood as a combination of the embodiments to explain the connotation of a larger structure or method of the present invention.

[0025] Example 1

[0026] An amide conductive grease with low friction and low contact resistance, the conductive grease comprises a basic conductive grease and a composite conductive grease, the basic conductive grease is formed by mixing a base oil and a thickener, the composite conductive grease is formed by mixing a base oil, a thickener and additives; the thickener is synthesized by amidation reaction of fatty acids and amines in a certain proportion.

[0027] Example 2

[0028] Based on Example 1, this example discloses that: the molar ratio of fatty acids to amines is 3:1.

[0029] Example 3

[0030] Based on Examples 1 and 2, this example discloses that the base oil is one or more of polyalphaolefin, liquid paraffin, alkylated aromatic hydrocarbon, and perfluoropolyether.

[0031] Example 4

[0032] Based on Examples 1, 2, and 3, this example discloses that the fatty acids are one or more of oleic acid, ricinoleic acid, linoleic acid, and linolenic acid.

[0033] Example 5

[0034] Based on Examples 1, 2, 3, and 4, this example discloses that the amines are one or more of melamine, tetraethylenepentamine, pentaethylenehexamine, and hexaethyleneheptamine.

[0035] Example 6

[0036] Based on Examples 1, 2, 3, 4, and 5, this example discloses that the additive includes one or more of hydroxylated carbon nanotubes (MWCNTs-OH), graphene, reduced graphene oxide (r-GO), fullerene, carbon black, and metal particles.

[0037] Example 7

[0038] Based on Example 6, this embodiment discloses that the metal particles include one or more of copper powder, silver powder, molybdenum disulfide, and tungsten disulfide.

[0039] Example 8

[0040] Based on embodiments 1, 2, 3, 4, 5, 6, and 7, this embodiment discloses:

[0041] The mass proportion of the additive is 1% of the total mass of the composite conductive grease.

[0042] The mass of the thickener accounts for 20% of the total mass of the basic conductive grease.

[0043] Example 9

[0044] Based on embodiments 1, 2, 3, 4, 5, 6, and 7, this embodiment discloses:

[0045] The mass of the additive accounts for 10% of the total mass of the composite conductive grease.

[0046] The mass of the thickener accounts for 60% of the total mass of the basic conductive grease.

[0047] Example 10

[0048] Based on the above embodiments, this embodiment discloses a method for preparing an amide conductive grease with low friction and low contact resistance, comprising the following steps:

[0049] (1) Basic conductive grease (such as Figure 1 The synthesis steps are as shown:

[0050] (1.1) Add 8.5 g of base oil and 1.7 g of melamine (MA) into a beaker and stir mechanically until the two are fully mixed;

[0051] (1.2) Add 8.5 g of base oil and 10.2 g of oleic acid (OA) into a beaker and stir mechanically until the two are fully mixed;

[0052] (1.3) Add the mixed solution of step (1.2) dropwise into the beaker of step (1.1), stir mechanically until the reaction is complete, and continue stirring to cool to room temperature.

[0053] (2) Composite conductive grease (such as Figure 1 Synthesis steps:

[0054] (2.1) Add 8.5 g of base oil and 1.7 g of melamine (MA) into a beaker and stir mechanically until the two are fully mixed;

[0055] (2.2) Add 8.5 g of base oil and 10.2 g of oleic acid (OA) into a beaker and stir mechanically until the two are fully mixed;

[0056] (2.3) Add the mixed solution of step (2.2) dropwise into the beaker of step (2.1), stir in a water bath until the reaction is complete, add the additive material into the beaker of step (2.1), continue stirring and cool to room temperature.

[0057] Embodiment 11

[0058] In the first step, 5 to 10 parts by weight of PAO10 and 1 to 3 parts by weight of melamine or tetraethylene pentamine, pentaethylene hexamine are added to a 100 mL beaker, stirred at 110°C for a period of time, and thoroughly mixed. In the second step, 4 to 6 parts by weight of oleic acid or linolenic acid, linoleic acid and 5 to 10 parts by weight of PAO10 are added to a 100 mL beaker, stirred at 110°C for a period of time, and thoroughly mixed. Then the mixture obtained in the second step is slowly dripped into the mixture obtained in the first step. Stirring is continued at 110°C for 30 to 90 minutes to ensure complete reaction. Subsequently, the obtained product is stirred and cooled to room temperature, and the obtained product is homogenized using a three-roll mill to obtain a basic conductive grease.

[0059] Example 12

[0060] In the first step, 5 to 10 parts by weight of PAO10 and 1 to 3 parts by weight of melamine (MA) are added to a 100 mL beaker, and stirred at 110°C for a period of time to fully mix. In the second step, 4 to 6 parts by weight of oleic acid (OA) and 5 to 10 parts by weight of PAO10 are added to a 100 mL beaker, and stirred at 110°C for a period of time to fully mix. In the third step, the compound obtained in the second step is slowly dripped into the mixture obtained in the first step. Subsequently, 0.25 to 0.75 parts by weight of hydroxylated carbon nanotubes (MWCNTs-OH) are added to the product obtained in the third step, and stirring is continued at 80°C for 30 to 90 minutes to ensure complete reaction. After stirring and cooling to room temperature, the resulting product is homogenized using a three-roll mill to obtain a composite conductive grease.

[0061] like Figure 2 As shown, the basic conductive grease and the composite conductive grease prepared by the present invention can maintain a low friction coefficient and a low contact resistance under current-carrying conditions, and have good resistance to load changes, current changes, and frequency changes.

Claims

1. Amide conductive grease with low friction and low contact resistance, characterized by: The conductive grease includes a basic conductive grease and a composite conductive grease. The basic conductive grease is formed by mixing a base oil and a thickener, and the composite conductive grease is formed by mixing a base oil, a thickener and additives. The thickener is synthesized by amidation reaction of fatty acids and amines in a certain proportion.

2. The amide conductive grease with low friction and low contact resistance as claimed in claim 1, characterized in that: The molar ratio of the fatty acids to the amines is 3:

1.

3. The amide conductive grease with low friction and low contact resistance as claimed in claim 1, characterized in that: The base oil is one or more of polyalphaolefin, liquid paraffin, alkylated aromatic hydrocarbon and perfluoropolyether.

4. The amide conductive grease with low friction and low contact resistance as claimed in claim 1, characterized in that: The fatty acid is one or more of oleic acid, ricinoleic acid, linoleic acid and linolenic acid.

5. The amide conductive grease with low friction and low contact resistance as claimed in claim 1, characterized in that: The amines are one or more of melamine, tetraethylenepentamine, pentaethylenehexamine and hexaethyleneheptamine.

6. The amide conductive grease with low friction and low contact resistance as claimed in claim 1, characterized in that: The additives include one or more of hydroxylated carbon nanotubes (MWCNTs-OH), graphene, reduced graphene oxide (r-GO), fullerene, metal particles, and carbon black.

7. The amide conductive grease with low friction and low contact resistance as claimed in claim 6, characterized in that: The metal particles include one or more of copper powder, silver powder, molybdenum disulfide and tungsten disulfide.

8. The amide conductive grease with low friction and low contact resistance as claimed in claim 1, characterized in that: The mass proportion of the additive is 1%-10% of the total mass of the composite conductive grease.

9. The amide conductive grease with low friction and low contact resistance as claimed in claim 1, characterized in that: The mass of the thickener accounts for 20%-60% of the total mass of the basic conductive grease.

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