CN110205181B

CN110205181B - Ester group-containing benzothiazole derivative lubricating oil additive and preparation and application thereof

Info

Publication number: CN110205181B
Application number: CN201910490041.6A
Authority: CN
Inventors: 韩利芬; 赵鸿斌; 余磊; 郑培锦
Original assignee: Dongguan University of Technology
Current assignee: Dongguan University of Technology
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2021-08-27
Anticipated expiration: 2039-06-06
Also published as: CN110205181A

Abstract

The invention provides an ester-containing benzothiazole derivative lubricating oil additive and preparation and application thereof, wherein dialkylamine and carbon disulfide are reacted under alkaline conditions to obtain a dithionate; reacting 2-mercaptobenzothiazole with chloropropanol to obtain 3- (benzothiazole-2-ylthio) propyl-1-ol, and reacting the 3- (benzothiazole-2-ylthio) propyl-1-ol with chloroacetyl chloride to obtain 3- (benzothiazole-2-ylthio) propyl-2-chloroacetate; then 3- (benzothiazole-2-alkylthio) propyl-2-chloroacetate reacts with the salt of dithiocarbamic acid to obtain the compound with the general formula I

The ester group-containing benzothiazole derivative lubricating oil additive. The preparation method is simple, the process conditions are mild, the raw materials are easy to obtain, the synthesis cost is low, the synthesis yield is high, and the product is used as an extreme pressure, wear-resistant, friction-reducing and corrosion-resistant additive of lubricating oil, so that the bearing capacity of the base oil is obviously improved, and the wear-resistant and friction-reducing performances of the base oil are improved.

Description

Ester group-containing benzothiazole derivative lubricating oil additive and preparation and application thereof

Technical Field

The invention relates to a lubricating oil additive containing ester-group benzothiazole derivatives, and preparation and application thereof, wherein the derivatives can be widely applied to the fields of machinery, energy, environment, materials, chemical industry and the like, and are particularly suitable for being used as lubricating oil (grease) additives.

Background

The lubricating oil is of great importance and ubiquity in the industrial production process, and with the enhancement of environmental awareness of people, the lubricating oil and additives are also required to be environment-friendly as much as possible in the production, use and treatment processes. Zinc Dialkyl Dithiophosphate (ZDDP) is used as an antiwear additive for lubricating oils to improve the antiwear and anticorrosion properties of the oils, and its production cost is low, which has been recognized in the industry. However, ZDDP has unavoidable limitations during its use, so the development of new additives is of great importance.

The benzothiazole has good bearing capacity and lubricating property, and has the characteristics of oxidation resistance and corrosion resistance. The research shows that the derivative can improve the biodegradability of the mineral base oil and is a potential environment-friendly additive; in addition, the crude ortho ester is a functional group which can obviously improve the tribological performance of the additive, and simultaneously, the sulfur element and the aromatic ring have synergistic interaction, thereby being beneficial to improving the extreme pressure performance of the oil product. Therefore, the design of the functional groups is combined together, and the lubricating oil additive with high performance and environmental friendliness is expected to be designed and synthesized.

Disclosure of Invention

The invention aims to solve the technical problem of providing an ester-containing benzothiazole derivative lubricating oil additive and preparation and application thereof, wherein the derivative does not contain elements harmful to the environment and health, such as phosphorus, halogen, metal elements and the like, and has the characteristics of excellent performance and environmental friendliness.

In order to solve the technical problems, the technical scheme of the invention is as follows:

an ester group-containing benzothiazole derivative lubricating oil additive, which is characterized in that the ester group-containing benzothiazole derivative lubricating oil additive has a chemical structure shown as a general formula I:

wherein R is a straight chain or branched chain alkyl with 1-30C atoms.

The invention also provides a preparation method of the lubricating oil additive containing the ester-based benzothiazole derivative, which is characterized by comprising the following steps:

(1) under the action of alkali, dialkyl amine reacts with carbon disulfide to prepare an intermediate 1, and the structural general formula of the intermediate is as follows:

wherein R is a linear chain or branched chain alkyl with 1-30C atoms, and M is Na or K

(2) Under the action of alkali, 2-mercaptobenzothiazole reacts with 3-chloro-1-propanol to prepare an intermediate 2, and the structure of the intermediate is as follows:

(3) under the action of alkali, the intermediate 2 reacts with chloroacetyl chloride to prepare an intermediate 3, and the structure of the intermediate is as follows:

(4) and (3) reacting the intermediate 1 prepared in the step (1) with the intermediate 3 prepared in the step (2) to prepare the ester-containing benzothiazole derivative lubricating oil additive.

Preferably, in the step (1), the dialkylamine is di-n-butylamine, di-n-octylamine, or di-iso-octylamine.

Preferably, in the steps (1) to (4), the reaction medium for the reaction is one or a mixture of chloroform, dichloromethane, water, ethanol, tetrahydrofuran and acetone.

Preferably, in the step (4), the molar ratio of the intermediate 1 to the intermediate 3 is 0.8: 1-1.2.

Preferably, in the steps (1) to (4), the reaction temperature is-5 to 80 ℃.

Preferably, in the above technical scheme, the reaction time of the reaction in the steps (1) to (4) is 0.5 to 12.0 hours.

The invention also provides application of the lubricating oil additive containing the ester-based benzothiazole derivative, which is characterized in that the lubricating oil additive containing the ester-based benzothiazole derivative is used as a lubricating oil or a lubricating grease additive to be added into base oil independently or added into the base oil in a compounding way with other lubricating oil or lubricating grease additives.

In the above aspect, the ester group-containing benzothiazole derivative lubricating oil additive is preferably added in an amount of 0.1 to 10 wt% based on the total mass of the lubricating oil or grease.

Compared with the prior art, the invention has the following beneficial effects:

the lubricating oil additive containing the ester-based benzothiazole derivative has excellent thermal stability, corrosion resistance, extreme pressure, wear resistance and friction reduction performance, and is a lubricating oil additive with excellent comprehensive performance; the preparation process is simple, the reaction conditions are mild, the used raw materials are cheap and easy to obtain, and the synthesis yield is high; the derivative is phosphorus-free, halogen-free and ashless, and is an environment-friendly lubricating oil additive.

Description of the drawings:

FIG. 1 is a NMR chart of example 1.

FIG. 2 is a NMR chart of example 2.

FIG. 3 is a NMR chart of example 3.

FIG. 4 is a mass spectrum of example 1.

FIG. 5 is a mass spectrum of example 2.

FIG. 6 is a mass spectrum of example 3.

FIG. 7 is a scanning electron microscope image of the surface topography of the vegetable oil base oil.

FIG. 8 is a scanning electron microscope photomicrograph of the wear pattern of a base oil with 1.0 wt.% ZDDP lubricating oil additive.

FIG. 9 is a scanning electron microscope image of the surface topography of the plaque of an oil sample with 1.0 wt% of the additive prepared in example 1 added.

FIG. 10 is a scanning electron microscope image of the surface topography of an oil-like plaque with 1.0 wt% of the additive prepared in example 2 added.

FIG. 11 is a scanning electron microscope image of the surface topography of an oil-like plaque with 1.0 wt% of the additive prepared in example 3 added.

Detailed Description

The present invention will be described in detail with reference to specific embodiments, which are illustrative of the invention and are not to be construed as limiting the invention.

Example 1

A250 mL three-necked flask was charged with 0.05mol (6.45g) of di-n-butylamine, 0.06mol (2.40g) of sodium hydroxide and 50mL of THF in this order, and then 0.05mol (3.80g) of carbon disulfide was added dropwise thereto under ice-cooling, followed by stirring and reacting for 3.0 hours. And after the reaction is finished, filtering, and performing rotary evaporation on the filtrate to remove the solvent to obtain the sodium dithionite.

0.05mol (8.35g) of 2-mercaptobenzothiazole and 60mL of 10 mass percent NaOH aqueous solution are sequentially added into a 250mL three-necked flask, the temperature is increased to 65 ℃, the stirring is carried out for 0.5h, 0.05mol (4.70g) of 3-chloro-1-propanol is dropwise added, the temperature is increased to 80 ℃, and the stirring reaction is carried out for 10 h. After the reaction, the mixture was filtered, extracted with ethyl acetate, washed with saturated brine several times, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed to give 3- (benzothiazol-2-ylthio) propyl-1-ol.

A250 mL three-necked flask was charged with 0.05mol (11.25g) of 3- (benzothiazol-2-ylthio) propyl-1-ol, 0.06mol (6.06g) of triethylamine, and 60mL of chloroform in this order, and 0.06mol (6.72g) of chloroacetyl chloride was added dropwise in an ice bath, followed by stirring and reacting for 3.0 hours. After the reaction, the reaction mixture was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed from the filtrate to obtain 3- (benzothiazol-2-ylthio) propyl-2-chloroacetate.

The sodium salt of the dithiocarbamic acid and 50mL of THF are sequentially added into a 250mL three-necked flask, the 3- (benzothiazol-2-ylthio) propyl-2-chloroacetate is added dropwise at room temperature, and after the stirring reaction is carried out for 0.5h, the temperature is increased, the reflux is carried out, and the stirring reaction is carried out for 5.0 h. After completion of the reaction, the solvent was distilled off under reduced pressure, and the residue was dissolved in ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed from the filtrate to obtain 20.64g of a yellow oily compound in 87.6% yield.¹H NMR(400MHz,CDCl₃)δ7.85(d,J＝8.0Hz,1H),7.73(d,J＝7.9Hz,1H),7.38(d,J＝7.3Hz,1H),7.28(d,J＝7.9Hz,1H),4.34–4.31(m,2H),4.14(s,2H),3.90(s,2H),3.65(s,2H),3.45–3.41(m,2H),2.21(dd,J＝8.3,4.8Hz,2H),1.73–1.64(m,4H),1.34(dd,J＝15.4,7.7Hz,4H),0.97–0.90(m,6H).MALDI-TOF-MS,m/z:calcd for C₂₁H₃₀N₂O₂S₄[M+1]⁺:470.12,found:471.002。

Example 2

0.05mol (12.07g) of diisooctylamine, 0.06mol (2.40g) of sodium hydroxide and 50mL of THF are sequentially added into a 250mL three-necked bottle, 0.05mol (3.80g) of carbon disulfide is dropwise added under ice bath, and the mixture is stirred and reacted for 3.0 h. And after the reaction is finished, filtering, and performing rotary evaporation on the filtrate to remove the solvent to obtain the sodium dithionite.

The sodium salt of the dithiocarbamic acid and 50mL of THF are sequentially added into a 250mL three-necked flask, the 3- (benzothiazol-2-ylthio) propyl-2-chloroacetate is added dropwise at room temperature, and after the stirring reaction is carried out for 0.5h, the temperature is increased, the reflux is carried out, and the stirring reaction is carried out for 5.0 h. After the completion of the reaction, the solvent was distilled off under reduced pressure, and the residue was dissolved in ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed from the filtrate to obtain 25.61g of a yellow oily compound in 87.8% yield.¹H NMR(400MHz,CDCl₃)δ7.86(d,J＝8.1Hz,1H),7.74(d,J＝7.9Hz,1H),7.40(t,J＝7.6Hz,1H),7.32–7.25(m,1H),4.32(t,J＝5.4Hz,2H),4.16(s,2H),3.94(d,J＝6.8Hz,2H),3.65(d,J＝7.0Hz,2H),3.44(t,J＝6.7Hz,2H),2.29–1.96(m,4H),1.27(s,16H),0.89(d,J＝6.2Hz,12H).MALDI-TOF-MS,m/z:calcd for C₂₉H₄₆N₂O₂S₄[M+1]⁺:582.24,found:583.321。

Example 3

0.05mol (12.07g) of di-n-octylamine, 0.06mol (2.40g) of sodium hydroxide and 50mL of THF are sequentially added into a 250mL three-necked bottle, 0.05mol (3.80g) of carbon disulfide is dropwise added under ice bath, and the mixture is stirred and reacted for 3.0 h. And after the reaction is finished, filtering, and performing rotary evaporation on the filtrate to remove the solvent to obtain the sodium dithionite.

The sodium salt of the dithiocarbamic acid and 50mL of THF are sequentially added into a 250mL three-necked flask, the 3- (benzothiazol-2-ylthio) propyl-2-chloroacetate is added dropwise at room temperature, and after the stirring reaction is carried out for 0.5h, the temperature is increased, the reflux is carried out, and the stirring reaction is carried out for 5.0 h. After the completion of the reaction, the solvent was distilled off under reduced pressure, and the residue was dissolved in ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed from the filtrate to obtain 26.19g of a yellow oily compound with a yield of 89.8%.¹H NMR(400MHz,CDCl₃)δ7.88(d,J＝8.1Hz,1H),7.76(d,J＝8.0Hz,1H),7.46–7.38(m,1H),7.33–7.29(m,1H),4.34(t,J＝6.0Hz,2H),4.17(s,2H),3.95–3.87(m,2H),3.71–3.63(m,2H),3.46(t,J＝7.1Hz,2H),2.30–2.17(m,2H),1.77–1.69(m,4H),1.30(d,J＝5.4Hz,20H),0.89(d,J＝4.6Hz,6H).MALDI-TOF-MS,m/z:calcd for C₂₉H₄₆N₂O₂S₄[M+1]⁺:582.24,found:583.205。

The extreme pressure, wear resistance and friction reduction performance of the additive and the surface appearance of the ball-milled spots of the steel are as follows:

the ester group-containing benzothiazole derivative lubricating oil additive prepared in examples 1 to 3 and commercially available ZDDP were added to vegetable oil in an amount of 1.0% by mass to prepare a test oil sample. The maximum seizure-free load (P) of the lubricating oil was evaluated by a MS-10A type four-ball friction tester manufactured by Xiamen testing machine factory with reference to GB-3142-82_BValue) and sintering load (P)_DValue). The test conditions are room temperature (25 ℃), the rotating speed is 1450r/min, and the time is 10 s. The steel balls used in the test are standard grade II GCr15 steel balls produced by Shanghai Steel ball factories, the diameter is 12.7mm, and the hardness is 59-61 RC. P_BValue sum P_DThe results of the value tests are listed in table 1.

TABLE 1 maximum No-seize load (P)_BValue) and sintering load (P)_DValue)

Oil sample	P_B/N	P_D/N
			Vegetable oil	470	784
ZDDP	647	980
			Example 1	862	1235
Example 2	862	1235
			Example 3	862	1235

The results show that the ester group-containing benzothiazole derivatives are added into the vegetable oil, and the P of the vegetable oil_BAnd P_DThe values are greatly improved, which shows that the extreme pressure performance of the lubricating oil can be greatly improved by the additive in the embodiment 1-3, and the extreme pressure performance of the additive is superior to that of the traditional additive ZDDP.

The ester group-containing benzothiazole derivative lubricating oil additive prepared in examples 1 to 3 and commercially available ZDDP were added to vegetable oil in an amount of 1.0% by mass to prepare a test oil sample. The ball Wear Scar Diameter (WSD) was measured at a load of 392N, at a speed of 1450r/min and for a period of 30min on a four-ball friction tester, and the results are shown in Table 2 and the corresponding average friction coefficients are shown in Table 3.

TABLE 2 Steel ball scrub spot diameter (WSD)

Oil sample	WSD/mm
		Vegetable oil	1.405
ZDDP	0.782
		Example 1	0.792
Example 2	0.774
		Example 3	0.760

The results show that when the ester group-containing benzothiazole derivatives are added into vegetable oil, the WSD value of the vegetable oil is obviously reduced. The additive in the embodiment 1-3 can obviously improve the wear resistance of the lubricating oil, and the wear resistance of the lubricating oil is similar to that of the traditional additive ZDDP.

TABLE 3 mean coefficient of friction

Oil sample	Coefficient of friction
		Vegetable oil	0.122
ZDDP	0.097
		Example 1	0.070
Example 2	0.064
		Example 3	0.060

The result shows that when the ester group-containing benzothiazole derivative is added into vegetable oil, the average friction coefficient of the vegetable oil is obviously reduced. The additive of the embodiment 1-3 can improve the antifriction performance of the lubricating oil, and the antifriction performance is superior to that of the traditional additive ZDDP.

FIGS. 7-11 are scanning electron microscope images of the topography of the speckled surfaces of vegetable oils and oil samples with 1.0% of the 3 additives synthesized. The result shows that compared with the surface of the steel ball grinding spots lubricated by vegetable oil, the steel ball grinding spots lubricated by the vegetable oil containing the additive are shallow, the diameter of the grinding spots is small, the grinding marks are regular, and the number of the grinding marks is reduced, which indicates that the additive plays a role in wear resistance when being added into the vegetable oil.

Thermal stability of the additive:

the thermal stability of the additives prepared in examples 1 to 3 was examined using a TG209 type thermogravimetric analyzer manufactured by Germany Steady instruments manufacturing Ltd. The test conditions were: the nitrogen atmosphere and the temperature rise rate were 20 ℃/min, and the test results are shown in Table 4.

TABLE 4 thermal decomposition temperatures of additives

The result shows that the initial thermal decomposition temperature of the ester-containing benzothiazole derivative synthesized in the embodiment is 206-235 ℃, the final thermal decomposition temperature is 327-350 ℃, the thermal stability is good, the product is superior to the traditional additive ZDDP, and the product can meet the requirements of common working conditions.

Corrosion resistance of the additive:

the ester-containing benzothiazole derivatives prepared in examples 1 to 3 were added to vegetable oil in an amount of 1.0% by mass to prepare test oil samples. The corrosion test was carried out with reference to the method of GB/T5096-2017. The test results are shown in Table 5.

TABLE 5 copper sheet Corrosion test results

The results show that the corrosion rating of the oil samples containing 3 additives is 1a, indicating that all 3 additives have excellent corrosion resistance.

The present invention is illustrated in detail by the above examples, but the present invention is not limited to the above methods, i.e., it is not meant to imply that the present invention must be carried out depending on the above reaction conditions. It will be apparent to those skilled in the art that any modifications to the present invention, equivalent substitutions of reaction solvent catalysts and changes in the specific reaction conditions, etc., are within the scope and disclosure of the present invention.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. An ester group-containing benzothiazole derivative lubricating oil additive, which is characterized in that the ester group-containing benzothiazole derivative lubricating oil additive has a chemical structure shown as a general formula I:

wherein R is a straight chain or branched chain alkyl with 1-30C atoms.

2. The method of claim 1, comprising the steps of:

(2) Reacting 2-mercaptobenzothiazole with 3-chloro-1-propanol to prepare an intermediate 2, wherein the structure is as follows:

(3) reacting the intermediate 2 prepared in the step (2) with chloroacetyl chloride to prepare an intermediate 3, wherein the structure of the intermediate is as follows:

(4) and (3) reacting the intermediate 1 prepared in the step (1) with the intermediate 3 prepared in the step (3) to prepare the ester-containing benzothiazole derivative shown in the general formula I.

3. The method of claim 2, wherein in step (1), the dialkylamine is di-n-butylamine, di-n-octylamine, or diisooctylamine.

4. The method for preparing the lubricating oil additive containing the ester-based benzothiazole derivatives of claim 2, wherein in the steps (1) - (4), the reaction medium is one or more of chloroform, dichloromethane, water, ethanol, tetrahydrofuran and acetone.

5. The method for preparing the ester-containing benzothiazole derivative lubricating oil additive of claim 2, wherein in step (4), the molar ratio of intermediate 1 to intermediate 3 is 0.8: 1-1.2.

6. The method for preparing the ester-containing benzothiazole derivative lubricating oil additive of claim 2, wherein the reaction temperature in the steps (1) - (4) is-5 to 80 ℃.

7. The method of claim 2, wherein the reaction time of the reaction in steps (1) - (4) is 0.5-12.0 h.

8. The use of an ester-containing benzothiazole derivative lubricating oil additive of claim 1, wherein the ester-containing benzothiazole derivative lubricating oil additive is added to a base oil as a lubricating oil or grease additive alone or in combination with other lubricating oil or grease additives.

9. The use of the lubricating oil additive containing ester-based benzothiazole derivatives of claim 8, wherein the amount of the lubricating oil additive containing ester-based benzothiazole derivatives added is 0.1-10 wt.% of the total mass of the lubricating oil or grease.