CN102061214B - Water-soluble lubricating additive and preparation method thereof - Google Patents

Abstract

The invention discloses a water-soluble lubricating additive and a preparation method thereof. The additive is a water-soluble thiophosphite compound; and by a molecular design method, a water-soluble group (CH2CH2O), active elements S and P and an adsorbent group -OH are introduced into the compound structure for synthesis, and the additive has good tribological properties.

Description

A kind of water-soluble lubricating additive and preparation method thereof

technical field

The invention relates to a water-soluble lubricating additive and its preparation method and application. the

Background technique

Water-based lubricants have attracted extensive attention in this century due to their excellent cooling performance, flame retardant, clean and low pollution, and wide range of sources. Based on the purpose of saving oil resources and protecting the environment, developed countries in the world are making great efforts to There has been considerable progress in the development of water-based lubricants, especially in the fields of hydraulic fluids and metalworking. At present, water-based metalworking fluids have occupied nearly 50% of the metalworking fluid market, and high water-based hydraulic fluids such as water-ethylene glycol have also been widely used in hydraulic transmission systems that work in high-fire-risk environments due to their flame-retardant advantages. use. However, due to the many characteristics of water different from oil, it is difficult for water to have the same lubricating effect as oil, and water itself is easy to rust metals. Therefore, the existing water-based lubricants generally have the problems of poor lubricity and rust resistance. The development and practical application of water-based lubricants are largely restricted. Therefore, research and development of high-performance water-soluble lubricant additives has important application value. the

In recent years, there have been many reports on the synthesis and tribological properties of water-soluble lubricant additives, such as Gao et al. (Y.J.Gao, Y.S.Jing, Z.J.Zhang, G.X.Chen, Q.J.Xue. 2002,253,576) have reported a kind of water-soluble imidazoline borate, and US Patent 6228818 has synthesized a kind of borate water-based lubricating additive, Huang etc. (W.J.Huang, J.X.Dong, F.F.Li, B.S.Chen.Study of the tribological behavior of S-(carboxylpropyl)-N-alkyl dithiocarbamic acid as additives in water-based fluid.Wear, 2002, 252, 306) prepared three kinds of water-soluble dithiocarbamate derivatives as water-based additives , US Patent 6852678 prepared a series of soft metal complexes as water-based additives with dithiocarbamic acid derivatives as ligands, US Patent 4729839 reported a sulfur-containing water-soluble lubricant additive, US Patent 6617288 reported a A water-soluble phosphorothioate compound, Jiang Haizhen (Jiang Haizhen. Research on new water-soluble anti-rust and anti-wear multifunctional additives. Doctoral dissertation of Shanghai University 2006) and others systematically studied the tribological properties and Anti-rust performance. Although these compounds can improve the tribological properties of water-based lubricating fluids to varying degrees as additives, they often have limited water solubility and need to be solubilized with surfactants, and they do not improve the overall performance of water-based lubricating fluids in terms of anti-wear and anti-friction. Obviously, there are different degrees of corrosion on metals, which is difficult to be applied in practice. the

Contents of the invention

The object of the present invention is to provide a water-soluble lubricating additive and a preparation method thereof. the

The present invention realizes by following measures:

In order to solve the above problems, we have prepared a water-soluble lubricant additive with excellent lubricating performance, simple preparation method, and can improve the overall anti-wear and friction-reducing performance of water-based lubricants. A water-soluble compound containing sulfur and phosphorus was synthesized by using a neutral group (CH2CH2O) _n , active elements S, P and an adsorption group -OH. It has good tribological properties as a water-soluble lubricating additive.

A water-soluble lubricating additive, characterized in that the additive is a water-soluble thiophosphite compound, represented by the general formula (VI), wherein R ₁ and R ₂ in the formula (VI) are the same or different straight chains of C8-C18 Alkyl or alkyl substituted phenyl, _R3 is H, phenyl or C1-C8 straight or branched chain alkyl, n is an integer of 10-20,

The preparation method of the compound of general formula (VI): carry out transesterification reaction with fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether or the mixture of the two and di-n-butyl phosphite in the presence of a catalyst, and then add Sulfur powder is vulcanized to obtain thiophosphite, which is further subjected to Mannich condensation with diethanolamine and aldehyde to obtain a water-soluble compound containing sulfur and phosphorus. the

A water-soluble lubricating additive specifically includes three reaction steps of A, B and C:

A uses fatty alcohol polyoxyethylene ether of formula (I) or alkylphenol polyoxyethylene ether of formula (II) or the mixture of the two and di-n-butyl phosphite of formula (III), in the presence of catalyst, React under reduced pressure at 120-160°C for 4-10 hours to generate the transesterification product of formula (IV), and use a decompression device to remove the by-product n-butanol during the whole process. In the formula (I), R' is a straight line of C8-C18 Chain or branched chain alkyl, R" in formula (II) is C2～C12 straight chain or branched chain alkyl;

B uses the phosphite ester of formula (IV) and sulfur powder to react for 4 to 10 hours at 120～160° C. under nitrogen atmosphere to generate the phosphorothioate ester of formula (V):

C uses the phosphorothioate of formula (V) to react with diethanolamine and aldehyde at 80 to 120° C. for 4 to 8 hours to generate a water-soluble phosphorothioate compound product of general formula (VI), wherein R ₃ is H , phenyl or C1-C8 straight-chain or branched-chain alkyl;

In step A of the method for preparing general formula (VI), the molar ratio of fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether or a mixture of the two to di-n-butyl phosphite is 2.0-2.3:1. the

In step A of the method for preparing general formula (VI), the catalyst used is sodium methoxide, sodium ethoxide or potassium tert-butoxide, and the amount of the catalyst used is 0.5% to 1% of the total mass of reactants. the

In step C of the method for preparing general formula (VI), the aldehyde used is formaldehyde, benzaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, heptanal or octanal. the

The water-soluble thiophosphite compound of the general formula (VI) can be used as a water-soluble lubricating additive, especially used in water-based metalworking fluids, high-water-based hydraulic fluids or drilling fluids, and has excellent lubricating properties, and has good effect on black Metal has good rust resistance. the

The compound of formula (VI) of the present invention is added to water, water and ethylene glycol mixed solution, water and polyethylene glycol mixed solution to form a lubricating system, which can obtain excellent anti-friction performance, good load-bearing capacity, and can be used for ferrous metals Has a good anti-rust effect. the

When the compound of formula (VI) of the present invention is used as a water-soluble lubricating additive in water-based metalworking fluid, high-water-based hydraulic fluid or drilling fluid, its addition amount is 1% to 10% of the mass of the water-based fluid. the

The compound of formula (VI) of the present invention is a water-soluble lubricating additive with excellent performance, and has good antirust function for ferrous metals. Compared with the existing water-soluble lubricating additives, the water-soluble additives synthesized by the present invention have good solubility in water, and the system is clear and transparent after dissolving, and has excellent stability. There is no impurity or precipitation during long-term storage, and the extremely low Excellent anti-wear and anti-friction effect can be obtained by adding the amount, especially suitable for water-based metalworking fluids, high-water-based hydraulic fluids or drilling fluids and other fields. the

Description of drawings

Fig. 1～Fig. 6 is that concentration is respectively 1%, 2%, 3%, 4%, 5%, the aqueous solution of the embodiment 1 product of 6% on SRV-IV micro-vibration friction and wear testing machine at 25 ℃, frequency 50Hz, The relationship curve of the friction coefficient changing with the load under the working condition of the amplitude of 1mm. the

Fig. 7～Fig. 12 is that concentration is respectively 1%, 2%, 3%, 4%, 5%, the aqueous solution of the product of embodiment 1 of 6% in SRV-IV micro-vibration friction and wear testing machine at 25 ℃, frequency 50Hz, The friction coefficient of long grinding for 20 minutes under the condition of amplitude 1mm and load 300N. the

Detailed ways

Example 1

Add 0.2mol di-n-butyl phosphite, 0.42mol octylphenyl polyoxyethylene ether (n=10, M=646.85g/mol ), 2g of potassium tert-butoxide, and the temperature was raised to 140° C. under agitation to start the decompression reaction. After this, the whole reaction process system was in a decompression state of 0.08 MPa until no by-products evaporated to stop the reaction. After cooling down to 60°C, add 0.2 mol of sulfur powder, feed N ₂ , raise the temperature to 150°C until the system is clear, stop the reaction, and obtain a light yellow transparent viscous liquid, the intermediate phosphorothioate.

Add 0.2mol diethanolamine and 0.22mol formaldehyde (37% solution) into a 500mL three-necked round-bottomed flask equipped with mechanical stirring, a thermometer and a condenser, stir at 60°C for 1.5 hours, and then slowly add 0.2mol of the prepared thio For the phosphite intermediate, the temperature was raised to 110°C for 5 hours, and the low-boiling point substances were removed by distillation under reduced pressure to obtain a reddish-brown viscous liquid, which was the Mannich condensation product of phosphite shown in general formula (VI), and its specific structure was:

Example 2

Add 0.2mol di-n-butyl phosphite, 0.42mol dodecyl polyoxyethylene ether (n=10, M=626.98g/mol ), 2g of potassium tert-butoxide, and the temperature was raised to 140° C. under agitation to start the decompression reaction. After this, the whole reaction process system was in a decompression state of 0.08 MPa until no by-products evaporated to stop the reaction. After cooling down to 60°C, add 0.2 mol of sulfur powder, feed N ₂ , raise the temperature to 150°C until the system is clear, and stop the reaction to obtain a light yellow viscous liquid, the intermediate phosphorothioate.

Add 0.2mol diethanolamine and 0.2mol benzaldehyde into a 500mL three-necked round-bottom flask equipped with mechanical stirring, a thermometer and a condenser, stir at 60°C for 1.5 hours, and then slowly add 0.2mol of the prepared phosphorothioate intermediate body, heated up to 110 ° C for 6 hours, and removed the low-boiling substances by distillation under reduced pressure to obtain a reddish-brown viscous liquid, which is the Mannich condensation product of phosphite shown in the general formula (VI), and its specific structure is:

Example 3

Add 0.2mol of di-n-butyl phosphite and 0.21mol of dodecyl polyoxyethylene ether (n=10, M=626.98g/mol) into a 500mL three-neck round bottom flask equipped with mechanical stirring, thermometer and water separator , 0.21mol nonylphenyl polyoxyethylene ether (n=10, M=660.85g/mol), 3g potassium tert-butoxide, heated up to 160°C under stirring conditions and started the depressurization reaction. After that, the whole reaction process system was at 0.08 MPa reduced pressure state, stop the reaction when no by-products are separated. After cooling down to 60°C, add 0.2 mol of sulfur powder, feed N ₂ , raise the temperature to 150°C, react until the system is clear, and stop the reaction to obtain a light yellow viscous liquid, the intermediate phosphorothioate.

Add 0.2mol diethanolamine and 0.2mol n-butyraldehyde into a 500mL three-necked round-bottomed flask equipped with mechanical stirring, a thermometer and a condenser, stir at 60°C for 1.5 hours, then slowly add 0.2mol of the prepared phosphorothioate The intermediate was heated to 110°C for 6 hours, and the low boiling point substances were removed by distillation under reduced pressure to obtain a red viscous liquid, which was the Mannich condensation product of phosphite shown in general formula (VI), and its specific structure was:

Tribological performance evaluation of the product:

The phosphite compound prepared in Example 1 was dissolved in distilled water, and prepared into an aqueous solution with a concentration of 1%, 2%, 3%, 4%, 5%, and 6%, and comprehensively evaluated its tribological properties:

1. According to the GB-3142-82 standard, the British Shell-Steta Four Ball EP lubricant Tester was used to test the concentrations of 1%, 2%, 3%, 4%, 5%, and 6% PB of the aqueous solution of the product of Example 1 , PD value, the steel ball used in the test is the GCr15 bearing steel secondary standard steel ball produced by Lanzhou Bearing Factory, its hardness is 59-61HRC, the test is carried out at room temperature, and the speed is 1450rpm. The results are listed in Table 1:

Table 1 The test results of the maximum non-seizing load (PB) and sintering load (PD) of different concentrations of water-based lubricants

It can be seen from the data in the table that this compound can greatly improve the carrying capacity and extreme pressure performance of water as an additive. Adding 1% can increase the maximum non-seizing load of water from less than 100N to nearly 600N. After the concentration is further increased, PB Gradually increased, the sintering load also rose to 2452N. the

2. Adopt the SRV-IV micro-vibration friction and wear testing machine test concentration that German Optimol oil company produces to be respectively 1%, 2%, 3%, 4%, 5%, the aqueous solution of the embodiment 1 product of 6% at 25 ℃, The relationship curve of friction coefficient f changing with load under the condition of frequency 50Hz and amplitude 1mm. The steel ball used in the test is GCr15 bearing steel with Φ=10mm, and the lower sample is GCr15 steel block with Φ24×8mm. The results are shown in Figures 1-6. It can be seen from the figure that during the program loading process, the additive exhibits excellent anti-wear and anti-friction properties. Although the load increases step by step, up to 1100N, the friction coefficient is relatively stable throughout the process, and the average friction coefficient It is around 0.100, and it tends to decrease with the increase of load. the

3. The SRV-IV micro-vibration friction and wear testing machine produced by Germany Optimol Grease Company is used to test the concentration of 1%, 2%, 3%, 4%, 5%, and 6% of the aqueous solution of the product of Example 1 at 25°C, Friction coefficient f when the frequency is 50Hz, the amplitude is 1mm, and the load is 300N for 20 minutes. The steel ball used in the test is GCr15 bearing steel with Φ=10mm. The results are shown in Figures 7-12. It can be seen from the figure that when sliding at a high frequency of 50Hz and a load of 300N, the compound can be used as an additive to lubricate the steel-steel friction pair very well, and the friction coefficient is extremely stable, stable at about 0.100, and the friction reduction effect is extremely obvious . the

Claims (1)

1. A water-soluble lubricating additive, characterized in that the additive is a water-soluble thiophosphite compound, represented by general formula (VI), and R ₁ and R ₂ are the same or different C8-C18 in the formula (VI). Straight-chain alkyl or alkyl-substituted phenyl, _R3 is H, phenyl or C1-C8 straight-chain or branched-chain alkyl, n is an integer of 10-20,

The preparation method of the compound of general formula (VI): carry out transesterification reaction with fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether or the mixture of the two and di-n-butyl phosphite in the presence of a catalyst, and then add Sulfur powder is vulcanized to obtain phosphorothioate, which is further obtained by Mannich condensation with diethanolamine and aldehyde. The method includes three reaction steps of A, B and C: A uses fatty alcohol polyoxyethylene ether of formula (I) or alkylphenol polyoxyethylene ether of formula (II) or the mixture of the two and di-n-butyl phosphite of formula (III), in the presence of catalyst, React under reduced pressure at 120-160°C for 4-10 hours to generate the transesterification product of formula (IV), and use a decompression device to remove the by-product n-butanol during the whole process. In the formula (I), R' is a straight line of C8-C18 Chain or branched chain alkyl, R” in formula (II) is C2～C12 straight chain or branched chain alkyl; fatty alcohol polyoxyethylene ether or alkylphenol polyoxyethylene ether or a mixture of the two and phosphorous acid di-normal The molar ratio of butyl ester is 2.0～2.3:1; The catalyst used is sodium methylate, sodium ethylate or potassium tert-butoxide, and the usage amount of catalyst is 0.5%～1% of the total mass of reactants;

B uses the phosphite of formula (IV) and sulfur powder to react for 4 to 10 hours at 120 to 160° C. under nitrogen atmosphere to generate the thiophosphite of formula (V):

C uses the phosphorothioate of formula (V) to react with diethanolamine and aldehyde at 80 to 120° C. for 4 to 8 hours to generate a water-soluble phosphorothioate compound product of general formula (VI), wherein R ₃ is H , phenyl or C1-C8 straight-chain or branched-chain alkyl; the aldehyde used is formaldehyde, benzaldehyde or n-butyraldehyde;

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