Application of dialkyl chain phosphate as gelator or lubricating oil additive, supramolecular gel lubricant and lubricating oil composition

Abstract

The invention relates to the technical field of lubricating materials, and provides application of dialkyl chain phosphate as a gelator or a lubricating oil additive, a supramolecular gel lubricant and a lubricating oil composition. According to the invention, the dialkyl chain phosphate is used as a gelator or a lubricating oil additive; phosphate ester molecules with relatively short alkyl chains can play a role of a lubricating oil additive, so that the antifriction and antiwear properties and the bearing capacity of the lubricating oil are enhanced; phosphate molecules with long alkyl chains can play a role of a gelator and prevent lubricating oil from creeping, volatilizing or leaking on the surfaces of parts, and meanwhile the obtained supramolecular gel lubricant has good thermal stability and mechanical stability and is high in antifriction and antiwear performance and bearing capacity. In conclusion, the dialkyl chain phosphate provided by the invention is expected to replace the existing lubricating additive, has important significance for efficient utilization of resources, and has potential application value for prolonging the service life of equipment.

Description

Technical Field

[0001] The invention relates to the technical field of lubricating materials, and in particular to the application of dialkyl chain phosphate as a gel factor or lubricating oil additive, a supramolecular gel lubricant and a lubricating oil composition. Background Art

[0002] Friction and wear are common in life and industry. They will cause a lot of energy loss and economic losses, and even cause serious mechanical accidents. Reasonable use of lubricants is one of the effective ways to reduce friction and wear. Usually, in order to improve the stability and lubrication performance of oil products, it is necessary to add a variety of lubricating additives, such as detergent dispersants, antioxidants and anticorrosives, viscosity index improvers, pour point depressants, antifoaming agents, emulsifiers, extreme pressure antiwear agents, etc. Among them, extreme pressure antiwear agents can effectively reduce mechanical friction and wear and prevent sintering.

[0003] In addition, in order to solve the problems of easy creep migration and leakage of lubricating oil, a class of supramolecular gel lubricants has been developed in recent years. It introduces multiple functional groups such as hydroxyl, amide group, urea group, benzene ring, etc. into the long alkyl chain through molecular design. While ensuring the compatibility of the gel factor with the base oil, it can also self-assemble under the action of hydrogen bonds, van der Waals forces, π-π stacking, static electricity, etc., to obtain an intricate three-dimensional network structure, which restrains the lubricating oil, prevents its creeping behavior on the surface of parts, and improves the use efficiency of the lubricating oil. Therefore, the preparation of a new supramolecular gel lubricant with excellent self-restraint performance, extreme pressure performance, and friction reduction and anti-wear performance is of great significance to the sustainable development of the national economy.

[0004] At present, common gel factors include aliphatic diamide compounds, amino acid urea derivatives, polyhydroxy compounds, etc.; common extreme pressure anti-wear agents include sulfur-based extreme pressure agents, phosphorus-based extreme pressure agents, chlorine-based extreme pressure agents, organic metal salt extreme pressure agents, etc., such as sulfurized fatty acid esters, chlorinated alkanes, phosphites, etc. According to literature and patent research, dialkyl phosphates are usually used as surfactants, and there has never been any report on dialkyl chain phosphates in lubricant additives and supramolecular gel lubricants. Summary of the invention

[0005] In view of this, the present invention provides the use of dialkyl chain phosphate as a gel factor or lubricant additive, a supramolecular gel lubricant and a lubricant composition. The present invention uses dialkyl chain phosphate as a gel factor or lubricant additive to reduce the friction coefficient and reduce wear; when used as a gel factor, it can also prevent the lubricant from creeping, volatilizing or leaking, and has broad application prospects.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] Application of dialkyl chain phosphate as gel factor or lubricating oil additive, the structure of the dialkyl chain phosphate is shown in Formula I:

[0008]

[0009] In formula I: R represents an alkyl chain having 8 to 18 carbon atoms;

[0010] When the carbon number of R in the formula I is 8, the dialkyl chain phosphate is used as a lubricating oil additive; when the carbon number of R in the formula I is 9 to 18, the dialkyl chain phosphate is used as a gel factor.

[0011] Preferably, the number of carbon atoms of R in Formula I is 8, 14, 16 or 18.

[0012] Preferably, the dialkyl chain phosphate is one or more of dioctyl phosphate, ditetradecyl phosphate, dihexadecyl phosphate and dioctadecyl phosphate.

[0013] Preferably, when the number of carbon atoms of R in Formula I is 8, the preparation method of the dialkyl chain phosphate comprises the following steps:

[0014] Octanol and phosphorus pentoxide are mixed for esterification reaction to obtain the dialkyl chain phosphate; the molar ratio of the octanol to phosphorus pentoxide is 4 to 4.5:1; and the esterification reaction time is 18 to 24 hours.

[0015] Preferably, when the number of carbon atoms of R in Formula I is 9 to 18, the preparation method of the dialkyl chain phosphate comprises the following steps:

[0016] The alcohol with carbon number of 9 to 18 is heated to liquid state, and then phosphorus pentoxide is added to carry out the first stage reaction and the second stage reaction in sequence to obtain the dialkyl chain phosphate; the molar ratio of the alcohol with carbon number of 9 to 18 and phosphorus pentoxide is 4 to 4.5:1; the temperature of the first stage reaction is 50 to 60°C, and the temperature of the second stage reaction is 70 to 80°C; the time of the second stage reaction is 18 to 24 hours.

[0017] The present invention also provides a supramolecular gel lubricant, comprising a base oil and a gel factor; the structure of the gel factor is shown in Formula I:

[0018]

[0019] In formula I: R represents an alkyl chain having 9 to 18 carbon atoms.

[0020] Preferably, the mass fraction of the gel factor in the supramolecular gel lubricant is 1 to 15%.

[0021] Preferably, the base oil comprises one or more of polyalphaolefins, mineral oils and polyol esters.

[0022] The present invention also provides a lubricating oil composition, comprising a base oil and a lubricating oil additive; the structure of the lubricating oil additive is shown in Formula I:

[0023]

[0024] In formula I: R represents an alkyl chain having 8 carbon atoms.

[0025] Preferably, the mass fraction of the lubricating oil additive in the lubricating oil composition is 1-5%; and the base oil includes one or more of mineral oil and polyol ester.

[0026] The present invention provides the application of dialkyl chain phosphate as a gelling factor or lubricating oil additive, wherein the structure of the dialkyl chain phosphate is shown in Formula I (see above); in Formula I, R represents an alkyl chain with a carbon number of 8 to 18; when the carbon number of R in Formula I is 8, the dialkyl chain phosphate is applied as a lubricating oil additive; when the carbon number of R in Formula I is 9 to 18, the dialkyl chain phosphate is applied as a gelling factor. The present invention strictly controls the chain length of the alkyl chain in the dialkyl phosphate, and realizes the application of the dialkyl chain phosphate in lubricating oil; specifically, the phosphate molecule with a shorter alkyl chain (with a carbon number of 8) can play the role of a lubricating oil additive, has good compatibility with a variety of base oils, and exerts excellent lubrication performance during friction, and has lower friction and wear compared with some existing commercial additives. Phosphate molecules with longer alkyl chains (9 to 18 carbon atoms) can play the role of gelling factors, completely dissolve in base oil at high temperatures, and self-assemble into a criss-cross three-dimensional network structure under low temperature conditions to play a limiting role on the base oil, preventing the lubricating oil from creeping, volatilizing or leaking on the surface of parts, and obtaining a self-constrained supramolecular gel lubricant. During the friction process, the supramolecular gel lubricant is thinned under the action of continuous shear force, and part of the gelling factor and base oil are transferred to the friction surface to play the role of lubricating additives, and also have excellent lubricating properties. In summary, the present invention uses dialkyl chain phosphate as a gelling factor or lubricating oil additive, which is expected to replace some existing commercial lubricating additives, and is of great significance to the efficient utilization of resources, and has potential application value in extending the service life of equipment.

[0027] The present invention also provides a supramolecular gel lubricant, comprising a base oil and a gel factor. The supramolecular gel lubricant provided by the present invention can prevent the lubricating oil from creeping, volatilizing or leaking on the surface of parts, has good thermal stability and mechanical stability, and has strong anti-friction and anti-wear properties and load-bearing capacity.

[0028] The present invention also provides a lubricating oil composition, comprising the lubricating oil additive described in the above scheme. The lubricating oil additive of the present invention can greatly improve the load-bearing capacity and extreme pressure performance of the lubricating oil. DETAILED DESCRIPTION

[0029] The present invention provides an application of a dialkyl chain phosphate ester as a gel factor or a lubricating oil additive, wherein the structure of the dialkyl chain phosphate ester is shown in Formula I:

[0030]

[0031] In formula I: R represents an alkyl chain having 8 to 18 carbon atoms;

[0032] When the number of carbon atoms of R in the formula I is 8, the dialkyl chain phosphate is used as a lubricant additive, and the lubricant additive is specifically an extreme pressure additive or a friction and anti-wear additive; when the number of carbon atoms of R in the formula I is 9 to 18, the dialkyl chain phosphate is used as a gel factor.

[0033] In the present invention, the number of carbon atoms of R in the formula I is preferably 8, 14, 16 or 18; the alkyl chain may be a straight chain alkyl or a branched chain alkyl, preferably a straight chain alkyl. Specifically, the dialkyl chain phosphate is one or more of dioctyl phosphate, ditetradecyl phosphate, dihexadecyl phosphate and dioctadecyl phosphate.

[0034] In the present invention, when the number of carbon atoms of R in Formula I is 8, the preparation method of the dialkyl chain phosphate preferably comprises the following steps:

[0035] Octanol and phosphorus pentoxide are mixed for esterification reaction to obtain the dialkyl chain phosphate; the molar ratio of the octanol to phosphorus pentoxide is 4 to 4.5:1; and the esterification reaction time is 18 to 24 hours.

[0036] In the present invention, the octanol is specifically n-octanol, and the obtained product is dioctyl phosphate; the temperature of the esterification reaction is preferably room temperature; the time of the esterification reaction can be specifically 18, 20, 22 or 24 hours; the esterification reaction is preferably carried out under mechanical stirring conditions.

[0037] In the present invention, when the number of carbon atoms of R in Formula I is 9 to 18, the preparation method of the dialkyl chain phosphate comprises the following steps:

[0038] The alcohol with carbon atoms of 9 to 18 is heated to a liquid state, and then phosphorus pentoxide is added to carry out a first-stage reaction and a second-stage reaction in sequence to obtain the dialkyl chain phosphate; the molar ratio of the alcohol with carbon atoms of 9 to 18 and phosphorus pentoxide is 4 to 4.5:1; the temperature of the first-stage reaction is 50 to 60°C, and the temperature of the second-stage reaction is 70°C; the time of the second-stage reaction is 18 to 24 hours.

[0039] In the present invention, the alcohol having 9 to 18 carbon atoms can be an alcohol having 14, 16 or 18 carbon atoms, more specifically tetradecanol, hexadecanol or octadecanol; when the alcohol is tetradecanol, hexadecanol or octadecanol, the obtained product is specifically ditetradecyl phosphate, dihexadecanol or dioctadecyl phosphate; the heating temperature for heating the alcohol to a liquid state is preferably 50 to 60°C; the reaction time of the first stage is based on the reaction until the solution becomes a solid or a viscous liquid; the reaction time of the second stage can be specifically 18h, 20h, 22h or 24h.

[0040] After the second stage reaction is completed, the present invention preferably cools the reaction solution to room temperature, and then washes, filters and dries to obtain the dialkyl chain phosphate; the washing agent used in the washing is preferably acetonitrile or dichloromethane; in a specific embodiment of the present invention, ditetradecyl phosphate is preferably washed with acetonitrile, dihexadecyl phosphate is preferably washed with dichloromethane, and dioctadecyl phosphate is preferably washed with dichloromethane; the ditetradecyl phosphate, dihexadecyl phosphate and dioctadecyl phosphate are all white solids.

[0041] The present invention also provides a supramolecular gel lubricant, comprising a base oil and a gel factor (denoted as a phosphate-type gel factor); the structure of the gel factor is shown in Formula I:

[0042]

[0043] In formula I: R represents an alkyl chain having 9 to 18 carbon atoms.

[0044] In the present invention, the gel factor is preferably one or more of ditetradecyl phosphate, dihexadecyl phosphate and dioctadecyl phosphate; the mass fraction of the gel factor in the supramolecular gel lubricant is preferably 1-15%; in a specific embodiment of the present invention, when the gel factor is ditetradecyl phosphate, the mass fraction of ditetradecyl phosphate in the supramolecular gel lubricant is preferably 3%-15%; when the gel factor is dihexadecyl phosphate, the mass fraction of dihexadecyl phosphate in the supramolecular gel lubricant is preferably 1%-10%; when the gel factor is dioctadecyl phosphate, the mass fraction of dioctadecyl phosphate in the supramolecular gel lubricant is preferably 2%-10%.

[0045] In the present invention, the base oil in the supramolecular gel lubricant includes one or more of polyalphaolefin, mineral oil and polyol ester; the polyalphaolefin may specifically be one or more of PAO2, PAO4, PAO10 and PAO40; the mineral oil may specifically be one or more of 500SN, 150BS, 150N, 500N and white oil; the polyol ester may specifically be NP451 and / or A51.

[0046] In the present invention, the preparation method of the supramolecular gel lubricant preferably comprises the following steps: adding the gel factor to the base oil, heating and stirring until the gel factor is completely dissolved, and then cooling to room temperature to obtain the supramolecular gel lubricant; the temperature of the heating and stirring is preferably 120-140°C, more preferably 130°C.

[0047] The present invention also provides a lubricating oil composition, comprising a base oil and a lubricating oil additive; the structure of the lubricating oil additive is shown in Formula I:

[0048]

[0049] In formula I: R represents an alkyl chain having 8 carbon atoms.

[0050] In the present invention, R in Formula I is preferably n-octyl, the lubricating oil additive is specifically dioctyl phosphate, and the mass fraction of the lubricating oil additive in the lubricating oil composition is preferably 1-5%; the base oil preferably includes one or more of mineral oil and polyol ester; the mineral oil preferably includes one or more of 500SN, 150BS, 150N, 500N and white oil; the polyol ester preferably includes NP451 and / or A51.

[0051] 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.

[0052] Example 1

[0053] The structural formula of ditetradecyl phosphate (C14) is:

[0054]

[0055] White solid, 1HNMR (400MHz, Chloroform-d) δ4.34-3.39 (m, 4H), 1.75-0.96 (m, 48H), 0.88 (t, J = 6.7Hz, 6H).

[0056] 0.1 mol (21.876 g) of tetradecanol was placed in a 250 mL round-bottom flask and dissolved at 50°C. After complete dissolution, 0.025 mol (3.552 g) of phosphorus pentoxide was added to the flask and magnetically stirred until the solution became a viscous liquid. The temperature was raised to 60°C and heated with stirring for 24 h. After the reaction was completed, it was slowly cooled to room temperature to obtain a white solid. The solid was washed with acetonitrile, filtered and dried to obtain a white solid product, ditetradecyl phosphate.

[0057] Example 2

[0058] The structural formula of dicetyl phosphate (C16) is:

[0059]

[0060] White solid, 1 HNMR (400MHz, Chloroform-d) δ4.40-3.32 (m, 4H), 1.25 (s, 56H), 0.88 (t, J = 6.6Hz, 6H).

[0061] 0.1 mol (24.490 g) of hexadecanol was placed in a 250 mL round-bottom flask and dissolved at 60 °C. After complete dissolution, 0.025 mol (3.552 g) of phosphorus pentoxide was added to the flask and stirred magnetically until the solution became solid. The temperature was raised to 70 °C and heated with stirring for 24 h. After the reaction was completed, the solution was slowly cooled to room temperature to obtain a white solid. The solid was washed with dichloromethane, filtered and dried to obtain a white solid product, dihexadecyl phosphate.

[0062] Example 3

[0063] The structural formula of dioctadecyl phosphate (C18) is:

[0064]

[0065] White solid, 1 HNMR(400MHz,Chloroform-d)δ4.02(q,J=6.8Hz,4H),1.25(s,64H),0.88(t,J=6.7Hz,6H).

[0066] 0.05 mol (13.6611 g) of octadecyl alcohol was placed in a 250 mL round-bottom flask and dissolved at 60 °C. After complete dissolution, 0.012 mol (1.776 g) of phosphorus pentoxide was added to the flask and stirred magnetically until the solution became solid. The temperature was raised to 70 °C and heated with stirring for 24 h. After the reaction was completed, it was slowly cooled to room temperature to obtain a white solid. The solid was washed with dichloromethane, filtered and dried to obtain a white solid product, dioctadecyl phosphate.

[0067] Example 4

[0068] The structural formula of dioctyl phosphate (C8) is:

[0069]

[0070] Transparent liquid, 1 HNMR(500MHz,Chloroform-d)δ4.05(dd,J=8.7,4.8Hz,2H),3.73(dt,J=45.4,6.9Hz,2H), 1.66(dp,J=48.1,6.8Hz,4H), 1.34(dtt,J=21.8,14.6,7.2Hz,22H), 0.91(t,J=6.7Hz,6H).

[0071] 0.05 mol (6.5773 g) of octanol was placed in a 250 mL round-bottom flask, and then 0.012 mol (1.776 g) of phosphorus pentoxide was added to the flask. The mixture was mechanically stirred for 24 h, and the resulting transparent liquid was dioctyl phosphate.

[0072] Example 5 Gelation performance of phosphate-type gelling factor

[0073] In order to prove the gelling performance of phosphate gelling factors in different base oils, the gelling performance experiments were carried out with different base oils polyalphaolefins (PAO2, PAO4, PAO10, PAO40), mineral oils (500SN, 150BS, 150N, 500N, white oil) and polyol esters (NP451, A51) at different mass ratios. The specific steps are as follows:

[0074] The gel factor and base oil were weighed according to the mass ratio and put into a 10 mL sample bottle. The oil and gel factor were mechanically stirred at 130 °C until the gel factor was completely dissolved. The mixed solution was taken out and allowed to stand, and slowly cooled to room temperature to obtain a supramolecular gel lubricant. The experimental results are shown in Table 1.

[0075] Table 1 Minimum gelling concentration of phosphate ester gelling factor in different base oils

[0076]

[0077] It can be seen from Table 1 that the three gel factors can form stable gel lubricants with the tested base oils. Different gel factors have different gel concentrations in different base oils. Among them, the minimum gel mass percentage of C14 in the base oil is between 3% and 15%, the minimum gel mass percentage of C16 in the base oil is between 1% and 10%, and the minimum gel mass percentage of C18 in the base oil is between 2% and 10%.

[0078] Example 6

[0079] In order to prove the thermal stability of the supramolecular gel lubricant, the thermal decomposition temperature and phase transition temperature of the phosphate type supramolecular gel lubricant were characterized by thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC). Taking PAO10 supramolecular gel lubricant as an example, the test results are shown in Table 2; in Table 2, taking C14-8%@PAO10 as an example, C14-8%@PAO10 means that the gel factor is C14, and the mass percentage of C14 in the base oil PAO10 is 8%. The preparation method of the supramolecular gel lubricant is the same as that of Example 5. The meanings of the remaining supramolecular gel lubricants in Table 2 are similar and will not be repeated here.

[0080] Table 2 Phase transition temperature and thermal decomposition temperature of supramolecular gel lubricant

[0081]

[0082] As can be seen from Table 2, the phase transition temperature of the supramolecular gel lubricant increases with the increase of the carbon chain length of the gel factor, and the minimum phase transition temperature (T g-s ) is 49.8℃, indicating that the supramolecular gel lubricant can maintain a stable gel state at room temperature. d ) are all over 270℃, indicating that the supramolecular gel lubricant has good thermal stability.

[0083] Example 7

[0084] In order to prove the thermal stability of the lubricating oil additive, the thermal decomposition temperature of the synthesized lubricating oil additive (C8) and commercial additives (T304, T306, 1R349) was tested, and the test results are shown in Table 3. In Table 3, taking C8-1%@500SN as an example, C8-1%@500SN means that the addition amount of lubricating oil additive C8 in base oil 500SN is 1%; the preparation method is: stir the C8 additive in 500SN at room temperature until it is completely dissolved, and then C8-1%@500SN can be obtained; the meanings of the other lubricating oils in Table 3 are similar, and will not be repeated here; the preparation methods are the same as C8-1%@500SN.

[0085] Table 3 Thermal decomposition temperature of C8 additives and commercial additives

[0086]

[0087] As can be seen from Table 3, compared with 500SN, the thermal decomposition temperature of the lubricant increased after adding C8 additive. Compared with commercial additives, the thermal decomposition temperature is similar, indicating that the additive has good thermal stability.

[0088] Example 8

[0089] In order to prove the mechanical stability of the supramolecular gel lubricant, the rheological test of the synthesized supramolecular gel lubricant was carried out using Anton Paar MCR302 rheometer. The rotor model used was PP25, and the gap was set to 1mm. The relationship between the elastic modulus G′ and G" with shear stress and frequency was measured using oscillation mode, the relationship between the elastic modulus G′ and G" with temperature was measured using temperature mode, and the viscosity of the gel lubricant was measured using rotation mode.

[0090] The specific experimental conditions are as follows:

[0091] (a) Variable shear stress: temperature: 25°C, frequency: 1Hz, shear stress: 0.001-100Pa; (b) Variable temperature: temperature: 0-130°C, frequency: 1Hz, shear stress: 5Pa; (c) Variable frequency: temperature: 25°C, frequency: 0.01-100Hz, shear stress: 5Pa. The supramolecular gel lubricant tested in this embodiment is shown in Table 4. Taking C14-5%@500SN as an example, C14-5%@500SN means that the gel factor is C14, and the mass percentage of C14 in the base oil 500SN is 5%. The preparation method of the supramolecular gel lubricant is the same as that of Example 5.

[0092] Table 4 Rheological data of supramolecular gel lubricant

[0093]

[0094] It can be seen from Table 4 that the supramolecular gel lubricant provided by the present invention has good mechanical stability.

[0095] Example 9

[0096] The lubrication performance of the phosphate ester supramolecular gel lubricant of the present invention was evaluated by using the SRV-V micro-vibration friction and wear tester produced by the German Optimol Grease Company. The supramolecular gel lubricant of different concentrations was used for the experiment, and the base oil was selected as the control sample. The wear volume of the following samples was measured by a three-dimensional optical profilometer.

[0097] The specific experimental operation process is as follows:

[0098] The test conditions selected in the tribological experiments are: (a) constant load: load: 200 N, temperature 25 °C, frequency 25 Hz, amplitude 1 mm, test time 30 min; (b) variable load: load: 100-2000 N, rate 3 min / 50 N, temperature 25 °C, frequency 25 Hz, amplitude 1 mm; (c) variable temperature: load: 200 N, temperature 20-160 °C, rate 2 min / 20 °C, frequency 25 Hz, amplitude 1 mm; (d) variable frequency: load: 200 N, temperature 25 °C, frequency 5-50 Hz, rate: 3 min / 5 Hz, amplitude 1 mm. The upper test ball in the test is a Φ10mm AISI 52100 steel ball; in the steel / steel friction pair, the lower test sample is a Φ24mm, 7.9mm thick AISI 52100 steel block with a hardness of 700-750HV; the wear volume of the lower test sample is measured by a three-dimensional optical profilometer, and the wear spot morphology is measured by an electron scanning microscope. Taking 500SN and PAO10 and the corresponding gel lubricants as examples, the experimental results are shown in Tables 5-12. The meanings of the various gel lubricants in the table are the same as those in the previous embodiment and will not be repeated here.

[0099] It can be seen from Tables 5 and 6 that the friction coefficient and wear volume of the supramolecular gel lubricant provided by the present invention are much smaller than those of the base oil, indicating that the supramolecular gel lubricant has excellent friction reduction and anti-wear properties. It can be seen from Tables 7 and 8 that the supramolecular gel lubricant greatly improves the load-bearing capacity of the base oil, and the extreme pressure load-bearing capacity of the supramolecular gel lubricant exceeds 1000N, indicating that the supramolecular gel lubricant has excellent extreme pressure performance. It can be seen from Tables 9 to 12 that under high temperature and high frequency conditions, the supramolecular gel lubricant can still maintain a stable friction coefficient, indicating that the supramolecular gel lubricant has stable tribological properties.

[0100] Table 5 Average friction coefficient and wear volume of 500SN and 500SN gel lubricant under 200N condition

[0101]

[0102] Table 6 Average friction coefficient and wear volume of PAO10 and PAO10 gel lubricant under 200N condition

[0103]

[0104] Table 7 Average friction coefficient of 500SN and 500SN gel lubricant under variable load conditions

[0105]

[0106] Table 8 Average friction coefficient of PAO10 and PAO10 gel lubricant under variable load conditions

[0107]

[0108]

[0109] Table 9 Average friction coefficient of 500SN and 500SN gel lubricant under variable temperature conditions

[0110]

[0111] Table 10 Average friction coefficient of PAO10 and PAO10 gel lubricant under variable temperature conditions

[0112]

[0113] Table 11 Average friction coefficient of 500SN and 500SN gel lubricant under variable frequency conditions

[0114]

[0115] Table 12 Average friction coefficient of PAO10 and PAO10 gel lubricant under variable frequency conditions

[0116]

[0117] Example 10

[0118] The tribological properties of the C8 lubricant additive of the present invention were evaluated using an SRV-V micro-vibration friction and wear tester produced by Optimol Grease Company of Germany. Base oil and commercial lubricant additives of the same type (T304, T306, 1R349) were selected as control samples. The wear volume of the following samples was measured by a three-dimensional optical profilometer.

[0119] The specific experimental operation process is as follows:

[0120] The test conditions selected in the tribological experiments are: (a) constant load: load: 400 N, temperature 25 °C, frequency 25 Hz, amplitude 1 mm, test time 30 min; (b) variable load: load: 50-2000 N, rate 3 min / 50 N, temperature 25 °C, frequency 25 Hz, amplitude 1 mm; (c) variable temperature: load: 200 N, temperature 25-200 °C, rate 5 min / 25 °C, frequency 25 Hz, amplitude 1 mm; (d) variable frequency: load: 200 N, temperature 25 °C, frequency 5-100 Hz, rate: 5 min / 5 Hz, amplitude 1 mm. The upper test ball in the test is a Φ10 mm AISI52100 steel ball; in the steel / steel friction pair, the lower test sample is a Φ24 mm, 7.9 mm thick AISI 52100 steel block with a hardness of 700-750 HV; the wear volume of the lower test sample is measured by a three-dimensional optical profilometer, and the wear spot morphology is measured by an electron scanning microscope. The experimental results are shown in Tables 13 to 16. The meanings of the various lubricating oils in Tables 13 to 16 are the same as those in Example 7, and are not repeated here.

[0121] It can be seen from Table 13 that compared with 500SN, the friction coefficient of the lubricant after adding C8 additive is significantly reduced, and the wear volume is reduced by 86.1% to 91.8%. This shows that the additive has excellent anti-friction and anti-wear properties. Table 14 shows the extreme pressure properties of the lubricant and the lubricant after adding the additive. When the additive concentration reaches 3%, the failure load can reach 2000N, which greatly improves the extreme pressure performance of the base oil. And compared with commercial additives, the extreme pressure performance is excellent. It can be seen from Tables 15 and 16 that under high temperature and high frequency conditions, the lubricant with the addition of C8 additive can still maintain a stable friction coefficient, indicating that the additive has stable tribological properties.

[0122] Table 13 Average friction coefficient and wear volume of 500SN and 500SN with additives under 400N condition

[0123]

[0124]

[0125] Table 14 Average friction coefficient of 500SN and 500SN with additives under variable load conditions

[0126]

[0127] Table 15 Average friction coefficient of 500SN and 500SN with additives under variable temperature conditions

[0128]

[0129] Table 16 Average friction coefficient of 500SN and 500SN with additives under variable frequency conditions

[0130]

[0131] Embodiment 11

[0132] The extreme pressure performance of the phosphate ester type supramolecular gel lubricant of the present invention was evaluated by using a MS-10A four-ball friction and wear tester. The gel lubricant of different concentrations was used for the experiment, and the base oil was selected as a control sample.

[0133] The specific experimental operation process is as follows:

[0134] The test conditions used in the tribological experiments are: (a) maximum bite load (P D ): rotation speed 1450rmp, room temperature; (b) sintering load (P B ): speed 1450rmp, room temperature; (c) constant load: load 461N, speed 1450rmp, room temperature, time 30min. The steel ball is made of AISI 52100 steel, with a diameter of 12.7mm and a hardness of 688-739HV. Taking 500SN and the corresponding gel lubricant as an example, the experimental results are shown in Table 17.

[0135] Table 17 shows that compared with the base oil, the maximum bite load of the gel lubricant is greatly improved, and the sintering load is also higher than the base oil. In addition, under constant load conditions, the average friction coefficient of the supramolecular gel lubricant is reduced by about 63%. The above data prove that the supramolecular gel lubricant has a high load-bearing capacity and excellent extreme pressure performance.

[0136] Table 17 P of 500SN and supramolecular gel lubricants of different concentrations B , P D and the average friction coefficient

[0137] project <![CDATA[P B (N)]]> <![CDATA[P D (N)]]> Average friction coefficient 500SN 431 1236 0.194 C14-5%@500SN 1667 1962 0.074 C14-6%@500SN 1667 1962 0.070 C14-7%@500SN 1570 1962 0.070

[0138] Example 12

[0139] The extreme pressure performance of the lubricating oil additive of the present invention was evaluated by using a MS-10A four-ball friction and wear tester. Base oil and commercial additives were selected as controls.

[0140] The specific experimental operation process is as follows:

[0141] The test conditions used in the tribological experiments are: (a) maximum bite load (P D ): rotation speed 1450rmp, room temperature; (b) sintering load (P B): speed 1450 rpm, room temperature. The steel ball is made of AISI 52100 steel, with a diameter of 12.7 mm and a hardness of 688-739 HV. The experimental results are shown in Table 18.

[0142] According to Table 18, compared with the base oil, the maximum bite load of the C8 additive is greatly improved, and the sintering load is also higher than the base oil. Compared with commercial additives, the maximum bite load of the C8 additive is the highest; but the sintering load is lower than that of the T304 additive. In summary, the additive has good extreme pressure performance.

[0143] Table 18 P of 500SN and 500SN with additives B and P D

[0144]

[0145]

[0146] According to the above embodiments, the present invention uses a dialkyl chain phosphate with a longer alkyl chain (the number of carbon atoms in the R group is 9 to 18) as a gel factor, which can prevent the lubricating oil from creeping, volatilizing or leaking on the surface of the parts, and the obtained supramolecular gel lubricant has good thermal stability and mechanical stability, and has strong friction and anti-wear properties and load-bearing capacity; the use of a dialkyl chain phosphate with a shorter alkyl chain (the number of carbon atoms in the R group is 8) as a lubricating oil additive can enhance the friction and anti-wear properties and load-bearing capacity of the lubricating oil.

[0147] 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. Application of dialkyl chain phosphate as gel factor or lubricating oil additive, characterized in that: The structure of the dialkyl chain phosphate is shown in Formula I: In formula I: R represents an alkyl chain having 8 to 18 carbon atoms; When the carbon number of R in the formula I is 8, the dialkyl chain phosphate is used as a lubricating oil additive; when the carbon number of R in the formula I is 9 to 18, the dialkyl chain phosphate is used as a gel factor.

2. The use according to claim 1, characterized in that: The number of carbon atoms in R in Formula I is 8, 14, 16 or 18.

3. The use according to claim 1, characterized in that: The dialkyl chain phosphate is one or more of dioctyl phosphate, ditetradecyl phosphate, dihexadecyl phosphate and dioctadecyl phosphate.

4. The use according to claim 1, characterized in that: When the number of carbon atoms of R in Formula I is 8, the preparation method of the dialkyl chain phosphate comprises the following steps: Octanol and phosphorus pentoxide are mixed for esterification reaction to obtain the dialkyl chain phosphate; the molar ratio of the octanol to phosphorus pentoxide is 4 to 4.5:1; and the esterification reaction time is 18 to 24 hours.

5. The use according to claim 1, characterized in that: When the carbon number of R in Formula I is 9 to 18, the preparation method of the dialkyl chain phosphate comprises the following steps: The alcohol with carbon number of 9 to 18 is heated to liquid state, and then phosphorus pentoxide is added to carry out the first stage reaction and the second stage reaction in sequence to obtain the dialkyl chain phosphate; the molar ratio of the alcohol with carbon number of 9 to 18 and phosphorus pentoxide is 4 to 4.5:1; the temperature of the first stage reaction is 50 to 60°C, and the temperature of the second stage reaction is 70 to 80°C; the time of the second stage reaction is 18 to 24 hours.

6. A supramolecular gel lubricant, characterized in that: It includes base oil and gel factor; the structure of the gel factor is shown in Formula I: In formula I: R represents an alkyl chain having 9 to 18 carbon atoms.

7. The supramolecular gel lubricant according to claim 6, characterized in that: The mass fraction of the gel factor in the supramolecular gel lubricant is 1-15%.

8. The supramolecular gel lubricant according to claim 6, characterized in that: The base oil includes one or more of polyalphaolefins, mineral oils and polyol esters.

9. A lubricating oil composition, characterized in that: It includes base oil and lubricating oil additive; the structure of the lubricating oil additive is shown in Formula I: In formula I: R represents an alkyl chain having 8 carbon atoms.

10. The lubricating oil composition according to claim 9, characterized in that The mass fraction of the lubricating oil additive in the lubricating oil composition is 1-5%; the base oil includes one or more of mineral oil and polyol ester.

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