Gel lubricant capable of gelling at room temperature as well as preparation method and application of gel lubricant

Abstract

The invention relates to the technical field of lubricants, and provides a gel lubricant capable of gelling at room temperature as well as a preparation method and application of the gel lubricant. The gel lubricant provided by the invention comprises a component A and a component B, wherein the component A is prepared from the following raw materials: a lipoic acid derivative, alkyl boric acid and precursor oil; and the component B comprises benzene diborate and precursor oil. The gel lubricant provided by the invention has room-temperature gelation capacity, and when the gel lubricant is used, the lubricant in a solution state can be firstly coated in a mechanical part, so that tiny gaps and pores between the parts are fully filled with the lubricant, and then the lubricant is subjected to standing for gelation, so that creeping and leakage of the lubricant are avoided; the gel lubricant provided by the invention can adapt to complex mechanical structure changes, has excellent tribological properties, can significantly reduce the friction coefficient of base oil, is suitable for lubrication of various mechanical parts, is simple in preparation method, convenient to use and wide in application range, and has wide application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of lubricants, and in particular to a room temperature gel lubricant and a preparation method and application thereof. Background Art

[0002] In the industrial field, about one-third of energy consumption is used to overcome friction, and wear and tear will lead to increased maintenance and replacement costs of mechanical parts. Using efficient lubricating materials to reduce friction and wear is important for reducing energy loss, improving mechanical efficiency, and extending the service life of mechanical equipment.

[0003] As a new type of semi-solid lubricant, gel lubricant has excellent thixotropic properties, can avoid lubricant creep and leakage, and avoid high viscous resistance, and also has excellent lubrication performance. However, current gel lubricants need to be heated before they can gel. When used, they need to be heated to gel, and then applied to mechanical parts for lubrication. This method of gelling first and then applying makes it difficult for the gel lubricant to completely fill the tiny gaps and pores between parts, limiting the lubrication effect of the gel lubricant. Summary of the invention

[0004] In view of this, the present invention provides a room temperature gel lubricant and a preparation method and application thereof. The gel lubricant provided by the present invention can gel at room temperature, and when used, can be first coated on mechanical parts and then gel, can adapt to complex mechanical structure changes, and completely fill the tiny gaps and pores between parts, thereby achieving effective lubrication.

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

[0006] A room temperature gel lubricant comprises a component A and a component B; the raw materials for preparing the component A comprise a thioctic acid derivative, an alkyl boric acid and a precursor oil; the thioctic acid derivative is 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl) propionic acid hexadecyl ester; the mass fraction of the thioctic acid derivative in the raw materials for preparing the component A is 5% to 20%;

[0007] The B component comprises phenyl diboric acid ester and precursor oil; the mass fraction of phenyl diboric acid ester in the B component is 5% to 15%.

[0008] Preferably, the alkyl boronic acid comprises one or more of n-butyl boronic acid, n-hexyl boronic acid, n-octyl boronic acid and n-decyl boronic acid; the molar amount of the alkyl boronic acid is 30% to 70% of the molar amount of the lipoic acid derivative.

[0009] Preferably, the preparation method of the component A comprises: heating and mixing the lipoic acid derivative, the precursor oil and the alkyl boric acid and then cooling to obtain the component A.

[0010] Preferably, the preparation method of the B component comprises: mixing phenyldiboric acid, diol and precursor oil for esterification reaction to obtain the B component.

[0011] Preferably, the diol includes one or more of 1,2-decanediol, 1,2-dodecanediol, 1,2-tetradecanediol and 1,2-hexadecanediol; and the molar ratio of the phenylenediboric acid to the diol is 1:(2-2.1).

[0012] Preferably, the precursor oil in the component A and the component B is an ester oil.

[0013] Preferably, the ester oil includes one or more of diester lubricating oil, polyol ester lubricating oil and dipentaerythritol ester lubricating oil.

[0014] Preferably, the mass ratio of component A to component B is (1-2):1.

[0015] The present invention also provides a method for preparing the room temperature gel lubricant described in the above scheme, comprising the following steps: mixing component A and component B to obtain the room temperature gel lubricant.

[0016] The present invention also provides the use of the room temperature gel lubricant described in the above scheme or the room temperature gel lubricant prepared by the preparation method described in the above scheme in lubricating mechanical parts.

[0017] The present invention provides a room temperature gel lubricant, comprising component A and component B; the raw materials for preparing component A include thioctic acid derivatives, alkyl boronic acid and precursor oil; the thioctic acid derivative is 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl) propionic acid hexadecyl ester; the mass fraction of thioctic acid derivatives in the raw materials for preparing component A is 5% to 20%; the B component includes phenyl diboric acid ester and precursor oil; the mass fraction of phenyl diboric acid ester in component B is 5% to 15%. The gel lubricant provided by the present invention comprises component A and component B, wherein component A comprises thioctic acid derivatives and alkyl boronic acid, the thioctic acid derivatives can be ring-opened polymerized to form linear polymers, and part of the thioctic acid derivatives react with alkyl boronic acid to form boric acid esters, and after component A and component B are mixed, component A and component B undergo boric acid ester exchange reaction at room temperature, thereby forming a cross-linked network to gel the lubricant. The gel lubricant provided by the present invention has room temperature gelation capability. When in use, the lubricant in a solution state can be firstly coated on a mechanical part so that the lubricant can fully fill the tiny gaps and pores between the parts, and then the lubricant can be left to stand for gelation to avoid the creep and leakage of the lubricant. The gel lubricant provided by the present invention can adapt to changes in complex mechanical structures, and overcomes the disadvantage that semi-solid lubricants (grease, gel) are not convenient to fill into the tiny gaps and pores of parts. In addition, the gel lubricant provided by the present invention has excellent tribological properties, can significantly reduce the friction coefficient of the base oil, is suitable for the lubrication of various mechanical parts, and has a simple preparation method, is easy to use, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a test chart of the room temperature gelling performance of the gel lubricant prepared in Example 1;

[0019] Figure 2 The friction coefficient curves of diester lubricant A51 and the gel lubricants obtained in Examples 1 to 4 are shown. DETAILED DESCRIPTION

[0020] The invention provides a room temperature gel lubricant, comprising a component A and a component B; the raw materials for preparing the component A include a thioctic acid derivative, an alkyl boric acid and a precursor oil; the thioctic acid derivative is 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl) propionic acid hexadecyl ester; the mass fraction of the thioctic acid derivative in the component A is 5% to 20%;

[0021] The B component comprises phenyl diboric acid ester and precursor oil; the mass fraction of phenyl diboric acid ester in the B component is 5% to 15%.

[0022] In the present invention, the raw materials for preparing the A component include lipoic acid derivatives, and the lipoic acid derivatives are 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl) propionic acid hexadecyl ester, and the structural formula is shown in Formula I:

[0023]

[0024] The present invention has no special requirements on the preparation method of the lipoic acid derivatives, and the lipoic acid derivatives can be prepared by methods well known to those skilled in the art.

[0025] In the present invention, the mass fraction of the lipoic acid derivative in the raw material for preparing component A is 5% to 20% (the total mass of the lipoic acid derivative, alkyl boric acid and precursor oil in component A is 100%), and can be specifically 5%, 8%, 9%, 10%, 12%, 15% or 20%.

[0026] In the present invention, the raw material for preparing component A includes alkyl boric acid; the alkyl boric acid preferably includes one or more of n-butyl boric acid, n-hexyl boric acid, n-octyl boric acid and n-decyl boric acid; the molar amount of the alkyl boric acid is preferably 30% to 70% of the molar amount of the thioctic acid derivative, specifically 30%, 40%, 50%, 60% or 70%.

[0027] In the present invention, the component A includes a precursor oil, and the precursor oil is preferably an ester oil. The ester oil preferably includes one or more of diester lubricating oil, polyol ester lubricating oil and dipentaerythritol ester lubricating oil; in a specific embodiment of the present invention, the ester oil is preferably diester lubricating oil A51.

[0028] In the present invention, the preparation method of the component A preferably comprises: heating and mixing the lipoic acid derivative, the precursor oil and the alkyl boric acid and then cooling to obtain the component A; the heating and mixing temperature is preferably 120 to 150°C, specifically 120°C, 130°C, 140°C or 150°C, the heating and mixing time is preferably 10 to 30 minutes, specifically 15 minutes, 20 minutes or 25 minutes; the cooling is specifically cooling to room temperature.

[0029] In the present invention, the B component includes phenyl diborate; the mass fraction of phenyl diborate in the B component is 5% to 15%, specifically 5%, 8%, 10%, 15% or 15%.

[0030] In the present invention, the B component includes a precursor oil, and the precursor oil is preferably an ester oil, and the ester oil preferably includes one or more of diesters, polyol esters and dipentaerythritol esters; in a specific embodiment of the present invention, the ester oil is preferably a diester lubricant A51.

[0031] In the present invention, the preparation method of the B component preferably comprises: mixing phenylenediboric acid, a diol and a precursor oil for esterification reaction to obtain the B component; the phenylenediboric acid is preferably terephthalic acid; the diol preferably comprises one or more of 1,2-decanediol, 1,2-dodecanediol, 1,2-tetradecanediol and 1,2-hexadecanediol. In a specific embodiment of the present invention, the diol is preferably 1,2-decanediol, or preferably a mixture of 1,2-decanediol and 1,2-tetradecanediol, and the mixture is The molar ratio of 1,2-decanediol to 1,2-tetradecanediol is preferably 1:(1-1.1); the molar ratio of phenyldiboric acid to diol is preferably 1:(2-2.1); the temperature of the esterification reaction is preferably 120-150°C, specifically 120°C, 130°C, 140°C or 150°C; the time of the esterification reaction is preferably 10-30min, specifically 15min, 20min or 25min; after the esterification reaction is completed, the reaction solution is cooled to room temperature to obtain the B component.

[0032] In the present invention, the mass ratio of component A to component B is preferably (1-2):1, specifically 1:1, 1.5:1 or 2:1.

[0033] The present invention also provides a method for preparing the room temperature gel lubricant described in the above scheme, comprising the following steps: mixing component A and component B to obtain the room temperature gel lubricant.

[0034] In the present invention, the mixing is preferably carried out at room temperature, the mixing time is preferably 10 minutes, and the mixing is preferably stirring. In the present invention, after the A component and the B component are mixed, a solution lubricant is obtained, and then it can be gelled by standing at room temperature, and the standing time is preferably 6 hours; in a specific application embodiment of the present invention, after the A component and the B component are mixed, the solution lubricant is preferably applied to the mechanical parts, and then it is left to stand at room temperature to gel.

[0035] The present invention also provides the use of the room temperature gel lubricant described in the above scheme or the room temperature gel lubricant prepared by the preparation method described in the above scheme in lubricating mechanical parts.

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions 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.

[0037] In the following examples, hexadecyl 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl)propanoate was prepared by the following method:

[0038] Levodopa (10 mmol), p-toluenesulfonic acid (11 mmol) and hexadecanol (12 mmol) were suspended in toluene (50 mL) and heated under Dean Stark conditions for 24 h. Toluene was removed under reduced pressure to obtain a viscous liquid, which was dissolved in ethyl acetate (50 mL), refrigerated for 8 h, and the white solid was collected by filtration, which was p-toluenesulfonate of hexadecyl (3,4-dihydroxyphenyl) propionate (DOPA-TsOH). 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (10 mmol) was added to a solution of lipoic acid (10 mmol) in DMF (50 mL), followed by hydroxybenzotriazole (10 mmol). The solution was stirred at 0°C for 30 minutes, then at room temperature for 1.5 hours, and triethylamine (30 mmol) was added dropwise. DOPA-TsOH (10 mmol) was added, and the mixture was stirred at room temperature in the dark overnight. 50 mL of ethyl acetate (100 mL) was added, washed three times with water (50 mL), and the combined aqueous phase was re-extracted with ethyl acetate (20 mL). The combined organic phase was washed with brine (50 mL) and dried over anhydrous MgSO4. The solvent was removed under reduced pressure and the crude mixture was purified by column chromatography to obtain hexadecyl 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl)propanoate.

[0039] Example 1

[0040] 0.61 g of hexadecyl 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl)propionate and 0.06 g of n-butylboric acid were added to 6 g of diester lubricating oil A51, and the mixture was heated and stirred at 130° C. for 20 min to obtain component A.

[0041] 0.17 g of terephthaloboric acid and 0.36 g of 1,2-decanediol were added to 5 g of diester lubricating oil A51, and the mixture was heated and stirred at 130° C. for 20 min to obtain component B.

[0042] Mix 1g of component A and 1g of component B, stir at room temperature for 10 minutes, and let stand for 6 hours to obtain a gel lubricant.

[0043] Example 2

[0044] 0.61 g of hexadecyl 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl)propionate and 0.09 g of n-octylboric acid were added to 6 g of diester lubricant A51, and the mixture was heated and stirred at 130° C. for 20 min to obtain component A.

[0045] 0.17 g of terephthaloyl diboric acid, 0.18 g of 1,2-decanediol and 0.24 g of 1,2-tetradecanediol were added to 5 g of diester lubricating oil A51, and the mixture was heated and stirred at 130° C. for 20 min to obtain component B.

[0046] Mix 1g of component A and 1g of component B, stir at room temperature for 10 minutes, and let stand for 6 hours to obtain a gel lubricant.

[0047] Example 3

[0048] The preparation method of component A is the same as that of Example 1, and the preparation method of component B is the same as that of Example 2.

[0049] Mix 1g of component A and 1g of component B, stir at room temperature for 10 minutes, and let stand for 6 hours to obtain a gel lubricant.

[0050] Example 4

[0051] The preparation method of component A is the same as that of Example 2, and the preparation method of component B is the same as that of Example 1.

[0052] Mix 1g of component A and 1g of component B, stir at room temperature for 10 minutes, and let stand for 6 hours to obtain a gel lubricant.

[0053] Performance Testing

[0054] Room temperature gelling performance test: The photos of the components A and B in Example 1 after stirring and mixing for 10 minutes and standing at room temperature for 6 hours are shown in the following figure. Figure 1 shown; according to Figure 1 It can be seen that component A and component B are in a liquid state when they are just mixed, and form a gel after standing at room temperature for 6 hours, indicating that the gel lubricant of the present invention has good gelling performance at room temperature.

[0055] Friction coefficient test: The tribological properties of the gel lubricants obtained in Examples 1 to 4 were evaluated using an SRV-V micro-vibration friction and wear tester produced by the German Optimol Grease Company, and compared with diester lubricant A51. The test conditions were: load 200N, temperature 25°C, frequency 25Hz, amplitude 1mm, test time 30min, the upper test ball was a GCr15 steel ball, and the lower test sample was a GCr15 steel block.

[0056] The friction coefficient curve is as follows Figure 2 The average friction coefficient test results are shown in Table 1.

[0057] Table 1 Average friction coefficient of A51 and Examples 1 to 4

[0058] Sample No. A51 Example 1 Example 2 Example 3 Example 4 Average friction coefficient 0.1433 0.1309 0.1250 0.1255 0.1256

[0059] According to Table 1 and Figure 2 It can be seen from the data in that the gel lubricants prepared by the present invention all have a lower friction coefficient.

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A room temperature gel lubricant, characterized in that: The invention comprises component A and component B; the raw materials for preparing component A comprise thioctic acid derivatives, alkyl boric acid and precursor oil; the thioctic acid derivative is 2-(5-(1,2-dithiolan-3-yl)pentanamido)-3-(3,4-dihydroxyphenyl) propionic acid hexadecyl ester; the mass fraction of the thioctic acid derivative in the raw materials for preparing component A is 5% to 20%; The B component comprises phenyl diboric acid ester and precursor oil; the mass fraction of phenyl diboric acid ester in the B component is 5% to 15%.

2. The room temperature gel lubricant according to claim 1, characterized in that: The alkylboronic acid comprises one or more of n-butylboric acid, n-hexylboric acid, n-octylboric acid and n-decylboric acid; the molar amount of the alkylboric acid is 30% to 70% of the molar amount of the lipoic acid derivative.

3. The room temperature gel lubricant according to claim 1, characterized in that: The preparation method of the A component comprises: heating and mixing a lipoic acid derivative, a precursor oil and an alkyl boric acid and then cooling the mixture to obtain the A component.

4. The preparation method according to claim 1, characterized in that: The preparation method of the B component comprises: mixing phenyldiboric acid, diol and precursor oil and performing esterification reaction to obtain the B component.

5. The room temperature gel lubricant according to claim 4, characterized in that: The diol includes one or more of 1,2-decanediol, 1,2-dodecanediol, 1,2-tetradecanediol and 1,2-hexadecanediol; the molar ratio of the phenylenediboric acid to the diol is 1:(2-2.1).

6. The room temperature gel lubricant according to claim 1, characterized in that: The precursor oil in the A component and the B component is an ester oil.

7. The room temperature gel lubricant according to claim 6, characterized in that: The ester oil includes one or more of diester lubricating oil, polyol ester lubricating oil and dipentaerythritol ester lubricating oil.

8. The room temperature gel lubricant according to claim 1, characterized in that: The mass ratio of component A to component B is (1-2):

1.

9. The method for preparing the room temperature gel lubricant according to any one of claims 1 to 8, characterized in that: The following steps are involved: The A component and the B component are mixed to obtain the room temperature gel lubricant.

10. Use of the room temperature gel lubricant according to any one of claims 1 to 8 or the room temperature gel lubricant prepared by the preparation method according to claim 9 in lubrication of mechanical parts.

Images