Polyurea-based lubricating grease and preparation method thereof

Abstract

The invention provides polyurea-based lubricating grease and a preparation method thereof. The polyurea-based lubricating grease comprises the following components: (A) phosphate ester salt which accounts for 0.1-10% of the total weight of the polyurea-based lubricating grease; (B) an antioxidant accounting for 0.1%-10% of the total weight of the polyurea-based lubricating grease; (C) an antirust agent accounting for 0.1-5% of the total weight of the polyurea-based lubricating grease; (D) a polyurea-based thickening agent which accounts for 1-30% of the total weight of the polyurea-based lubricating grease; and (E) a lubricating base oil which constitutes the main component of the polyurea-based grease. The polyurea-based lubricating grease provided by the invention has excellent extreme pressure anti-wear performance and oxidation resistance, also has good colloid stability and mechanical stability, and can be competent for harsh working conditions such as high temperature, high speed, high load, wateriness and the like.

Description

Technical Field

[0001] The present invention relates to the field of greases, and particularly to a polyurea-based grease and a preparation method thereof. Background Art

[0002] Grease is a necessary working medium in the normal operation of mechanical equipment and the manufacturing and processing of materials. With the rapid development of industry, the demand for grease is also increasing. Since the thickener in polyurea-based grease does not contain metal ions, the catalytic oxidation of the base oil is avoided. Therefore, polyurea-based grease is widely used due to its good oxidation stability and thermal stability.

[0003] In recent years, with the progress of industrial technology, the working conditions of the parts where grease is used have become more and more severe, which puts higher requirements on lubricant additives. In particular, polyurea-based grease is required to have more excellent anti-wear performance. Therefore, developing polyurea-based grease with excellent anti-wear performance is still the research and development direction of those skilled in the art. Summary of the Invention

[0004] The present invention provides a polyurea-based grease and a preparation method thereof.

[0005] The polyurea-based grease of the present invention comprises the following components:

[0006] (A) Phosphate ester salt, accounting for 0.1% to 10% of the total weight of the polyurea-based grease, preferably 0.2% to 5%;

[0007] (B) Antioxidant, accounting for 0.1% to 10% of the total weight of the polyurea-based grease, preferably 0.2% to 5%;

[0008] (C) Rust inhibitor, accounting for 0.1% to 5% of the total weight of the polyurea-based grease, preferably 0.2% to 3%;

[0009] (D) Polyurea-based thickener, accounting for 1% to 30% of the total weight of the polyurea-based grease, preferably 3% to 20%;

[0010] (E) Lubricating base oil, which constitutes the main component of the polyurea-based grease;

[0011] Wherein the phosphate ester salt comprises a structural unit shown in formula (1), and at least one of the structural units shown in formula (2), formula (3) and formula (4),

[0012] Wherein, R1 and R2 are each independently selected from hydrogen, hydrocarbon group, substituted hydrocarbon group or heteroalkyl;

[0013] Among them, X1 is selected from nitrogen or methylene, R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R3, R4 and R5 are each independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0014] Among them, R6, R7 and R8 are each independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0015] Among them, R” is selected from hydrogen or a C1-C4 hydrocarbon group, R9, R 10 and R 11 are each independently selected from a C1-C5 hydrocarbon group, and r5 and r6 are each independently 0 or 1.

[0016] According to the present invention, the method for preparing the phosphate salt includes:

[0017] Contacting an acidic phosphate having the structure shown in formula (5) with a nitrogen-containing organic compound having a bicyclic structure to carry out a phosphate salt formation reaction;

[0018] Among them, R1 and R2 are each independently selected from hydrogen, a hydrocarbon group, a substituted hydrocarbon group or a heteroalkyl group;

[0019] Among them, the nitrogen-containing organic compound has at least one of the structures shown in formula (6), formula (7) and formula (8),

[0020] Among them, X1 is selected from nitrogen or methylene, R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R3, R4 and R5 are each independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0021] Among them, R6, R7 and R8 are each independently selected from a C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0022] Among them, R” is selected from hydrogen or a C1-C4 hydrocarbon group, R9, R 10 and R 11 are each independently selected from a C1-C5 hydrocarbon group, and r5 and r6 are each independently 0 or 1.

[0023] According to the present invention, the phosphate salt does not contain metal elements, is not prone to generate ash, shows significant anti-wear performance at a relatively small dosage, and can effectively improve the anti-wear performance and load-carrying capacity of lubricating oil. In addition, when the phosphate salt is used as an anti-wear additive for lubricating oil, it shows excellent anti-wear performance while having low metal corrosion.

[0024] According to the present invention, the antioxidant can be selected from one or more of N-phenyl-α-naphthylamine, alkylated diphenylamine, shielded phenol, and phenolic ester. For example, it can be selected from one or more of N-phenyl-α-naphthylamine, dibutyl diphenylamine, dioctyl diphenylamine, butyl / octyl diphenylamine, didodecyl diphenylamine, dipentyl diphenylamine, 2,6-di-tert-butyl-p-cresol, and 2,6-di-tert-butyl-4-hydroxyphenyl propionate.

[0025] According to the present invention, the rust inhibitor can be one or more of sulfonates, imidazoline alkenyl succinates, and benzotriazoles. For example, it can be selected from one or more of barium petroleum sulfonate, barium dinonylnaphthalene sulfonate, heptadecenyl imidazoline alkenyl succinate, and benzotriazole.

[0026] According to the present invention, the polyurea thickener is a reaction product of an organic amine and an isocyanate. The organic amine can be selected from one or more of C4-C 20 fatty amines, C6-C 20 aromatic amines, C4-C 20 cycloalkylamines, C4-C 20 polyene polyamines. For example, it can be selected from one or more of dodecylamine, tetradecylamine, octadecylamine, aniline, p-toluidine, cyclohexylamine, ethylenediamine, propylenediamine, and diethylenetriamine; the isocyanate can be selected from diphenylmethane-4,4'-diisocyanate and / or 2,4-toluene diisocyanate. The molar ratio between the organic amine and the isocyanate can be 1:0.2-5.

[0027] According to the present invention, the lubricating base oil can be one or more of mineral oil, vegetable oil, ester oil, and poly-α-olefin oil. It can be selected from lubricating base oils with a kinematic viscosity of 5-60 mm 2 / s at 100 °C, preferably lubricating base oils with a kinematic viscosity of 10-30 mm 2 / s at 100 °C.

[0028] The preparation method of the polyurea grease of the present invention includes: adding 1 / 3-2 / 3 of the lubricating base oil into a grease kettle and heating it up; optionally dissolving the organic amine and the isocyanate with the lubricating base oil respectively. When the temperature in the reaction kettle rises to 40-90 °C, add the organic amine or its mixed solution with the lubricating base oil, stir for 5-20 minutes, then add the isocyanate or its mixed solution with the lubricating base oil, carry out saponification reaction for 10-100 minutes, then add water to the reaction system, heat up to 180-220 °C for high-temperature refining for 10-60 minutes; add the remaining lubricating base oil, cool down to 100-120 °C, add phosphate ester salt, antioxidant, and rust inhibitor, stir evenly, and grind into grease through a three-roll mill.

[0029] According to the present invention, the addition amount of the water can be 5%-30% of the mass of the isocyanate.

[0030] The polyurea-based grease of the present invention has excellent extreme pressure and anti-wear properties and antioxidant properties, and at the same time has good colloidal stability and mechanical stability, and can be competent for harsh working conditions such as high temperature, high speed, high load, and multi-water. Detailed Description of the Invention

[0031] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0032] The present invention will be further described in detail below in conjunction with embodiments. However, the present invention is not limited thereto. Unless otherwise specified, all ratios and parts are by mass.

[0033] The first aspect of the present invention provides a phosphate salt, which includes a structural unit represented by formula (1), and at least one of the structural units represented by formula (2), formula (3), and formula (4).

[0034] Wherein, R1 and R2 are each independently selected from hydrogen, hydrocarbon group, substituted hydrocarbon group or heteroalkyl group;

[0035] Wherein, X1 is selected from nitrogen or methylene, R and R’ are each independently selected from hydrogen or C1-C4 hydrocarbon group; R3, R4 and R5 are each independently selected from C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0036] Wherein, R6, R7 and R8 are each independently selected from C1-C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0037] Wherein, R” is selected from hydrogen or C1-C4 hydrocarbon group, R9, R 10 and R 11 are each independently selected from C1-C5 hydrocarbon group, and r5 and r6 are each independently 0 or 1.

[0038] In the prior art, phosphate amine salts usually require a relatively high dosage when used as lubricant anti-wear additives. Through continuous research, the inventors of the present invention found that phosphate organic base salts with a nitrogen-containing bicyclic structure can exhibit remarkable anti-wear properties at a relatively low dosage level, effectively improving the anti-wear performance and load-carrying capacity of lubricants. This phosphate salt does not contain metal elements, is not prone to generating ash, and at the same time has low metal corrosion while showing excellent anti-wear performance, having outstanding progress compared to the phosphate amine salt compounds in the prior art.

[0039] In the present invention, R1 and R2 are each independently selected from hydrogen, hydrocarbon groups, substituted hydrocarbon groups, or heteroalkyl groups. Preferably, R1 and R2 are not both hydrogen at the same time.

[0040] Among them, the "hydrocarbon group" has the meaning conventionally known in the art, including but not limited to straight-chain or branched-chain alkyl groups, straight-chain or branched-chain alkenyl groups, straight-chain or branched-chain alkynyl groups, cycloalkyl groups, cycloalkenyl groups, cycloalkynyl groups, aryl groups, or their combined groups. Preferably, the hydrocarbon group is a C1-C20 hydrocarbon group, including but not limited to straight-chain or branched-chain alkyl groups of C1-C20, straight-chain or branched-chain alkenyl groups of C2-C20, straight-chain or branched-chain alkynyl groups of C2-C20, cycloalkyl groups of C3-C20, cycloalkenyl groups of C3-C20, cycloalkynyl groups of C3-C20, aryl groups of C6-C20, or their combined groups.

[0041] In the present invention, the "substituted hydrocarbon group" refers to a group obtained by directly substituting one or more hydrogens in a hydrocarbon group molecule with substituents, and the substituents include but not limited to at least one of fluorine atoms, chlorine atoms, bromine atoms, hydroxyl groups, mercapto groups, alkoxy groups, and alkylthio groups.

[0042] In the present invention, the "heteroalkyl group" refers to a group obtained by directly substituting one or more carbon atoms inside the alkyl group structure (excluding the ends of the main chain or any side chain in the alkyl group structure) with heteroatoms. It can be understood that from the perspective of structural stability, when there are multiple heteroatoms, these heteroatoms are not directly bonded to each other. In the present invention, although the number of carbon atoms in the alkyl group decreases due to the substitution of carbon atoms with heteroatoms, for the sake of simplicity of expression, the number of carbon atoms of the alkyl group before the substitution is still used to refer to the number of carbon atoms of the heteroalkyl group.

[0043] For example, a C4 straight-chain alkyl group such as (the group indicated by the arrow is at the end of the main chain) being directly substituted by a substituent group -O- will obtain -CH2-O-CH2-CH3 or -CH2-CH2-O-CH3, which is called a C4 straight-chain heteroalkyl group. Or, a C4 branched-chain alkyl group such as (the group indicated by the arrow is not inside the molecular structure but at the ends of the main chain and side chain) having a methylene group directly substituted by a substituent group -N< will obtain It is called a C4 branched-chain heteroalkyl group. According to the present invention, the heteroalkyl group includes, but is not limited to, a linear or branched heteroalkyl group having 3 to 20 carbon atoms, preferably a linear or branched heteroalkyl group having 3 to 10 carbon atoms.

[0044] Preferably, the heteroatom in the heteroalkyl group is at least one of O, N, and S, preferably O and / or S, and more preferably S.

[0045] According to the present invention, preferably, each of R1 and R2 is independently selected from a C4-C18 hydrocarbon group, a C4-C18 hydroxy-substituted hydrocarbon group, or a C3-C20 heteroalkyl group, including but not limited to n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, methylphenyl, or dimethylphenyl.

[0046] According to the present invention, in formula (2), each of r1 and r2 is independently 0 or 1. It can be understood that when r1 is 0, it means that the R4 group does not exist, and at this time, the N atom and the C atom on both sides of R4 in formula (2) are directly connected. Similarly, when r2 is 0, it means that the R5 group does not exist, and at this time, the N and X1 on both sides of R5 in formula (2) are directly connected. The meanings of r3, r4, r5, and r6 in formula (3) and formula (4) are the same as those of r1 and r2, and will not be elaborated here.

[0047] In the present invention, as long as the phosphate salt has a phosphate group and a nitrogen-containing bicyclic structure, the anti-wear performance of the lubricating oil can be improved, and the anti-wear performance and metal corrosion resistance can be further optimized by controlling the size (number of carbon atoms) of the bicyclic ring. For example, by adjusting the main-chain carbon number of the R3, R4, and R5 groups in formula (2), the size of the bicyclic structure in formula (2) can be controlled. Similarly, in the structures shown in formula (3) and formula (4), by adjusting the main-chain carbon number of the R6, R7, and R8 and R9, R 10 and R 11 groups, the size of the bicyclic structure in formula (2) and formula (3) can be controlled.

[0048] According to the present invention, preferably, in formula (2) - formula (4), each of R3, R6, and R9 is independently -(CH2) a -, where a is selected from 2 to 5.

[0049] According to the present invention, preferably, each of R4, R7, and R 10 is independently -(CH2) b -, where b is 1 to 2.

[0050] According to the present invention, preferably, R5, R8, R 11 are each independently -(CH2) c -, where c is 1 - 3.

[0051] Through the above-mentioned preferred number of rings and steric structures of the nitrogen-containing organic compounds, the basicity of such compounds and their dispersibility in base oils can be controlled, and nitrogen-containing organic compounds with sufficiently stable chemical properties can also be selected according to the use environment.

[0052] According to the present invention, the phosphate salt can exist, be manufactured, or be used in the form of a single (pure) compound, or can exist, be manufactured, or be used in the form of a mixture of two or more of them (in any proportion), which does not affect the realization of the effects of the present invention.

[0053] According to the present invention, there is no particular limitation on the preparation method of the phosphate salt, and it can be prepared by any known method in the art.

[0054] The second aspect of the present invention provides a method for preparing the phosphate salt, which method includes:

[0055] Contacting an acidic phosphate having the structure shown in formula (5) with a nitrogen-containing organic compound having a bicyclic structure to carry out a reaction for generating a phosphate salt;

[0056] wherein, R1 and R2 are each independently selected from hydrogen, a hydrocarbon group, a substituted hydrocarbon group, or a heteroalkyl group;

[0057] wherein, the nitrogen-containing organic compound has at least one of the structures shown in formula (6), formula (7), and formula (8),

[0058] wherein, X1 is selected from nitrogen or methine, R and R’ are each independently selected from hydrogen or a C1 - C4 hydrocarbon group; R3, R4, and R5 are each independently selected from a C1 - C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1;

[0059] wherein, R6, R7, and R8 are each independently selected from a C1 - C5 hydrocarbon group, and r3 and r4 are each independently 0 or 1;

[0060] wherein, R” is selected from hydrogen or a C1 - C4 hydrocarbon group, R9, R 10 and R 11 are each independently selected from a C1 - C5 hydrocarbon group, and r5 and r6 are each independently 0 or 1.

[0061] In the present invention, the acidic phosphate ester can be directly a commercially available product or can be manufactured by methods conventionally known in the art, and the present invention has no particular limitation thereon. In addition, the acidic phosphate ester can be used alone or in combination of two or more, as long as the structure shown in formula (5) is satisfied.

[0062] According to the present invention, preferably, in formula (5), R1 and R2 are not both hydrogen at the same time.

[0063] Preferably, R1 and R2 are each independently selected from a C4-C18 hydrocarbon group, a C4-C18 hydroxy-substituted hydrocarbon group or a C3-C20 heteroalkyl group.

[0064] Preferably, the heteroatom in the heteroalkyl group is at least one of O, N and S, preferably O and / or S, and more preferably S.

[0065] Preferably, R1 and R2 are each independently selected from n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, methylphenyl or dimethylphenyl.

[0066] According to the present invention, the acidic phosphate esters include but are not limited to monobutyl phosphate (CAS: 1623-15-0), dibutyl phosphate (CAS: 107-66-4), monoisobutyl phosphate (CAS: 2466-73-1), diisobutyl phosphate (CAS: 6303-30-6), monotert-butyl phosphate (CAS: 2382-75-4), ditert-butyl phosphate (CAS: 33494-81-4), monon-hexyl phosphate (CAS: 3900-04-7), di-n-hexyl phosphate (CAS: 3900-13-8), monophenyl phosphate (CAS: 701-64-4), diphenyl phosphate (CAS: 838-85-7), benzyl phosphate (CAS: 1623-07-0), dibenzyl phosphate (CAS: 1623-08-1), mono(methylphenyl) phosphate, di(methylphenyl) phosphate, monon-octyl phosphate (CAS: 3991-73-9), di-n-octyl phosphate (CAS: 3115-39-7), mono(2-ethylhexyl) phosphate (CAS: 1070-03-7), di(2-ethylhexyl) phosphate (CAS: 298-07-7), mono(1-methylheptyl) phosphate (CAS: 10353-73-8), di(1-methylheptyl) phosphate (CAS: 77076-28-9), mono(3,5,5-trimethylhexyl) phosphate (CAS: 85006-34-4), di(3,5,5-trimethylhexyl) phosphate (CAS: 7153-98-2), monon-decyl phosphate (CAS: 3921-30-0), di-n-decyl phosphate (CAS: 7795-87-1), monolauryl phosphate, dilauryl phosphate, myristyl phosphate, dimyristyl phosphate, mono(hexadecyl) phosphate, di(hexadecyl) phosphate, monostearyl phosphate, distearyl phosphate, mono(9-octadecenyl) phosphate, di(9-octadecenyl) phosphate, mono(9,12-octadecadienyl) phosphate, di(9,12-octadecadienyl) phosphate, mono(12-hydroxy-9-octadecenyl) phosphate and di(12-hydroxy-9-octadecenyl) phosphate, or isomers of the above compounds.

[0067] The present invention does not particularly limit the source of the nitrogen-containing organic compound having a bicyclic structure. Commercially available products can be directly used, or it can be manufactured by methods conventionally known in the art. The nitrogen-containing organic compound can be used alone, or two or more of them can be used in combination, as long as at least one of the structures shown in Formula (6), Formula (7) and Formula (8) is satisfied.

[0068] According to the present invention, preferably, in Formula (6)-Formula (8), R3, R6, and R9 are each independently -(CH2) a -, where a is selected from 2-5.

[0069] Preferably, R4, R7, R 10 are each independently -(CH2)b-, where b is 1 - 2.

[0070] Preferably, R5, R8, R 11 are each independently -(CH2)c-, where c is 1 - 3.

[0071] According to the present invention, the nitrogen-containing organic compound includes but is not limited to 1,4-diazabicyclo[2.2.2]octane (CAS: 280-57-9), 1-azabicyclo[2.2.2]octane (quinuclidine, CAS: 100-76-5), 1,5-diazabicyclo[4.3.0]-5-nonene (CAS: 3001-72-7), 1,8-diazabicyclo[5.4.0]undec-7-ene (abbreviation: DBU, CAS: 6674-22-2), and any proportion mixture of the above compounds.

[0072] In the present invention, preferably, the molar ratio of the acidic phosphate ester to the nitrogen-containing organic compound is 1:0.1 - 10, preferably 1:0.4 - 5, and more preferably 1:0.5 - 2.

[0073] The present invention has a relatively wide selection range for the reaction temperature of the reaction of the phosphate salt. Preferably, the reaction temperature is 0 - 200 °C, preferably 20 - 150 °C, and further preferably 60 - 120 °C; the present invention has no special requirements for the reaction time. To ensure sufficient reaction, preferably, the reaction time is 0.1 - 24 h, preferably 0.5 - 12 h, and further preferably 1 - 5 h.

[0074] The present invention has no particular limitation on the reaction pressure and atmosphere for the reaction of the phosphate salt, and it can be carried out under normal pressure and air conditions.

[0075] According to the present invention, the reaction of the phosphate salt can be carried out in the presence of a solvent or without the presence of a solvent, and the reaction can be achieved in both cases. Preferably, the reaction of the phosphate salt is carried out in the presence of a solvent. For example, the acidic phosphate ester and the nitrogen-containing organic compound are added to a reactor containing a solvent for contact, or the acidic phosphate ester and the nitrogen-containing organic compound are separately dissolved in a solvent, and then the two are added to the reactor for the reaction of the phosphate salt to occur. The present invention has no special requirements for the reactor, as long as the reaction conditions can be controlled within the above range, and conventional reaction devices in the art can be applied to the present invention.

[0076] The present invention has no special requirements for the specific operating conditions of adding the above reactants to the reactor, and the conventional operating methods in the art can be adopted. Preferably, the reactants are slowly added in batches or dropwise to the reactor, and the temperature is controlled within the above reaction temperature range.

[0077] The present invention also has no special limitation on the addition order of each reaction raw material, and they can be added in any order.

[0078] Preferably, the solvent is selected from at least one of C6-C10 alkanes, C6-C20 aromatic hydrocarbons, C5-C10 aliphatic ethers, C2-C20 halogenated hydrocarbons, and C3-C10 amides. The C6-C10 alkanes include but are not limited to at least one of n-hexane, cyclohexane, and petroleum ether; the C6-C20 aromatic hydrocarbons include but are not limited to at least one of benzene, toluene, xylene, and cumene; the C2-C20 halogenated hydrocarbons include but are not limited to at least one of dichloromethane, carbon tetrachloride, chlorobenzene, and 1,2-dichlorobenzene; the C5-C10 aliphatic ethers include but are not limited to at least one of methyl tert-butyl ether, 1,2-dimethoxyethane, ethylene glycol diethyl ether, and 1,4-dioxane; the C3-C10 amides include but are not limited to at least one of dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

[0079] According to the present invention, preferably, the mass ratio of the total mass of the acidic phosphate ester and the nitrogen-containing organic compound to the mass of the solvent is 1:0.5-10, preferably 1:0.5-5, and more preferably 1:0.8-3.

[0080] According to the present invention, only one kind of the solvent can be used, or a combination of two or more kinds can be adopted. Preferably, the preparation method further includes recovering the solvent after the reaction and recycling it to the same reaction. For example, the solvent can be recovered by vacuum distillation.

[0081] According to the present invention, in the preparation method of the phosphate salt, the obtained reaction product can be a single phosphate salt or a mixture containing multiple phosphate salts. These reaction products are all expected by the present invention. The phosphate salts all have the structural unit shown in formula (1) and at least one of the structural units shown in formula (2), formula (3), and formula (4). The different specific existence forms do not affect the realization of the effects of the present invention. Therefore, these reaction products are collectively referred to as the phosphate salts of the present invention in the context of this specification without distinction.

[0082] Therefore, in the present invention, the product obtained by reacting the phosphate salt can be purified or not. To further improve the performance of the phosphate salt, preferably, the preparation method further includes: purifying the product obtained by reacting the phosphate salt. A phosphate salt with a specific structure is separated from the product obtained by reacting the phosphate salt through the purification.

[0083] The purification can adopt any conventional purification or separation method in the art, and the present invention has no special limitation thereon. For example, column chromatography or preparative chromatography can be used to purify the reaction product.

[0084] The present invention will be described in detail below through examples.

[0085] In the following examples and comparative examples, unless otherwise specified, the raw materials used are all commercially available.

[0086] Example 1

[0087] In a 250 mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser, and a dropping funnel, 5.59 g (49.84 mmol) of 1,4-diazabicyclo[2.2.2]octane and 44.15 g of 1,2-dimethoxyethane were added and rapidly stirred and dissolved at room temperature; 25.02 g (100.00 mmol) of diphenyl phosphate dissolved in 49.09 g of 1,2-dimethoxyethane was slowly added dropwise to the three-necked flask; the temperature was raised to 85 °C, and the temperature was controlled to reflux between 80 - 85 °C for 4.5 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure, and 30.48 g of a white waxy product was obtained. The product was denoted as S1. The structure of the product was characterized by gas chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 350.12. According to the analysis, the structure of the main product in S1 is shown in the following formula:

[0088]

[0089] Example 2

[0090] In a 250 mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser, and a dropping funnel, 5.60 g (49.92 mmol) of 1,4-diazabicyclo[2.2.2]octane and 46.02 g of 1,2-dimethoxyethane were added and rapidly stirred and dissolved at room temperature; 32.21 g (99.90 mmol) of bis(2-ethylhexyl) phosphate was slowly added dropwise to the three-necked flask, and the temperature was raised to 85 °C, and the temperature was controlled to reflux between 80 - 85 °C for 4 hours. After the reaction was completed, the solvent was removed by distillation under reduced pressure, and 37.32 g of a white waxy product was obtained. The product was denoted as S2. The structure of the product was characterized by gas chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 434.38. According to the analysis, the structure of the main product in S2 is shown in the following formula:

[0091]

[0092] Example 3

[0093] In a 250 mL three-necked flask equipped with a magnetic stirrer, a thermometer, a condenser, and a dropping funnel, 5.61 g (50.13 mmol) of 1,4-diazabicyclo[2.2.2]octane and 45.52 g of 1,2-dimethoxyethane were added and rapidly stirred and dissolved at room temperature; 21.04 g (100.01 mmol) of dibutyl phosphate was slowly dropped into the three-necked flask, and the temperature was raised to 85 °C, and the temperature was controlled to reflux at 80 - 85 °C for 4 hours. After the reaction was completed, the solvent was distilled off under reduced pressure to obtain 26.06 g of a slightly yellowish, clear, transparent oily liquid product. The product was designated as S3. The structure of the product was characterized by gas chromatography-mass spectrometry, and the molecular weight of the main product was measured to be 321.99. According to the analysis, the structure of the main product in S3 is shown in the following formula:

[0094]

[0095] The sources of the main raw materials used in the following greases are as follows:

[0096] Octadecylamine, Beijing Innochem Science & Technology Co., Ltd., analytical pure

[0097] Dodecylamine, Aladdin Biochemical Technology Co., Ltd., analytical pure

[0098] Cyclohexylamine, TCI (Shanghai) Chemical Industry Development Co., Ltd., analytical pure

[0099] p-Toluidine, Aladdin Biochemical Technology Co., Ltd., analytical pure

[0100] Diphenylmethane-4,4'-diisocyanate, Wanhua Chemical Group Co., Ltd., industrial grade

[0101] T701, Barium petroleum sulfonate, Chengdu Xindu Petroleum Additive Factory, industrial grade

[0102] T705, Barium dinonylnaphthalene sulfonate, Suzhou Special Oil Products Factory, industrial grade

[0103] N-Phenyl-α-naphthylamine, Aladdin Biochemical Technology Co., Ltd., analytical pure

[0104] T534, Butyl / octyl diphenylamine, Beijing Xingpu Fine Chemical Technology Development Co., Ltd.

[0105] Example 4

[0106] Raw material components: 500SN 820.32 g (viscosity at 100 °C is 11 mm 2 / s); 100.03 g of octadecylamine; 48.17 g of diphenylmethane-4,4'-diisocyanate; 5.03 g of N-phenyl-α-naphthylamine; 5.21 g of barium dinonylnaphthalene sulfonate; 110.07 g of the product S1 of Example 1.

[0107] First, add 491.15 g of 500SN base oil to the fat-making kettle. When the temperature rises to 80 °C, stop heating. After dissolving 100.03 g of octadecylamine in 99.78 g of 500SN base oil by heating, add it to the fat-making kettle and stir for 10 minutes. Take 52.5 g of 500SN base oil, dissolve 48.17 g of diphenylmethane-4,4'-diisocyanate by heating, add it to the fat-making kettle, carry out saponification reaction for 30 minutes, then add 10 g of water to the fat-making kettle, raise the temperature to 205 °C for high-temperature refining for 15 minutes, add 176.64 g of 500SN base oil, cool down to 110 °C, add 5.03 g of N-phenyl-α-naphthylamine, 5.21 g of barium dinonylnaphthalene sulfonate, and 110.07 g of the product S1 of Example 1, stir evenly, and grind it into fat through a three-roll mill 3 times.

[0108] Example 5

[0109] Raw material components: 949.16 g of PAO10 (viscosity at 100 °C is 10 mm 2 / s); 79.92 g of octadecylamine; 20.11 g of cyclohexylamine; 66.01 g of diphenylmethane-4,4'-diisocyanate; 5.77 g of N-phenyl-α-naphthylamine; 6.19 g of barium dinonylnaphthalene sulfonate; 12.73 g of the product S2 of Example 2.

[0110] First, add 479.58 g of PAO10 base oil to the fat-making kettle. When the temperature rises to 50 °C, stop heating. After dissolving 79.92 g of octadecylamine in 81.25 g of PAO10 base oil by heating, add it to the fat-making kettle, then add 20.11 g of cyclohexylamine and stir for 10 minutes. Take 61.75 g of PAO10 base oil, dissolve 66.01 g of diphenylmethane-4,4'-diisocyanate by heating, add it to the fat-making kettle, carry out saponification reaction for 30 minutes, then add 10 g of water to the fat-making kettle, raise the temperature to 205 °C for high-temperature refining for 15 minutes, add 326.58 g of PAO10 base oil, cool down to 110 °C, add 5.77 g of N-phenyl-α-naphthylamine, 6.19 g of barium dinonylnaphthalene sulfonate, and 12.73 g of the product S2 of Example 2, stir evenly, and grind it into fat through a three-roll mill 3 times.

[0111] Example 6

[0112] Raw material components: 820.32 g of 500SN (viscosity at 100 °C is 11 mm 2 / s); 75.32 g of p-toluidine; 118.57 g of diphenylmethane-4,4'-diisocyanate; 5.36 g of butyl / octyl diphenylamine; 5.51 g of barium petroleum sulfonate; 11.13 g of the product S3 of Example 3.

[0113] First, add 461.25 g of 500SN base oil to the fat-making kettle. When the temperature rises to 70 °C, stop heating. After dissolving 75.32 g of p-toluidine in 90.37 g of 500SN base oil by heating, add it to the fat-making kettle and stir for 10 minutes. Take 120.47 g of 500SN base oil, heat and dissolve 118.57 g of diphenylmethane-4,4'-diisocyanate, add it to the fat-making kettle, carry out saponification reaction for 30 minutes, then add 10 g of water to the fat-making kettle, raise the temperature to 205 °C for high-temperature refining for 10 minutes, add 148.23 g of 500SN base oil, when the temperature drops to 110 °C, add 5.36 g of butyl / octyl diphenylamine, 5.51 g of barium petroleum sulfonate, and 11.13 g of the product S3 of Example 3, and stir evenly; grind through a three-roll mill 3 times to form a grease.

[0114] Example 7

[0115] Raw material components: 799.37 g of PAO4 (viscosity at 100 °C is 3.9 mm 2 / s); 75.12 g of dodecylamine; 53.24 g of diphenylmethane-4,4'-diisocyanate; 4.98 g of butyl / octyl diphenylamine; 5.07 g of barium petroleum sulfonate; 10.31 g of the product S3 of Example 3.

[0116] First, add 407.76 g of PAO4 base oil to the fat-making kettle. When the temperature rises to 70 °C, stop heating. After dissolving 75.12 g of dodecylamine in 77.39 g of PAO4 base oil by heating, add it to the fat-making kettle and stir for 10 minutes. Take 65.15 g of PAO4 base oil, heat and dissolve 53.24 g of diphenylmethane-4,4'-diisocyanate, add it to the fat-making kettle, carry out saponification reaction for 30 minutes, then add 10 g of water to the fat-making kettle, raise the temperature to 205 °C for high-temperature refining for 10 minutes, add 249.07 g of PAO4 base oil, when the temperature drops to 110 °C, add 5.36 g of butyl / octyl diphenylamine, 5.51 g of barium petroleum sulfonate, and 10.31 g of the product S3 of Example 3, stir evenly, and grind through a three-roll mill 3 times to form a grease.

[0117] Comparative Example 1

[0118] Raw material components: 949.16 g of PAO10 (viscosity at 100 °C is 10 mm 2 / s); 79.92 g of octadecylamine; 20.11 g of cyclohexylamine; 66.01 g of diphenylmethane - 4,4'-diisocyanate; 5.77 g of N - phenyl - α - naphthylamine; 6.19 g of barium dinonylnaphthalene sulfonate.

[0119] First, add 479.58 g of PAO10 base oil to the grease kettle. When the temperature rises to 50 °C, stop heating. Dissolve 79.92 g of octadecylamine in 81.25 g of PAO10 base oil by heating and then add it to the grease kettle. Then add 20.11 g of cyclohexylamine and stir for 10 minutes. Take 61.75 g of PAO10 base oil, heat and dissolve 66.01 g of diphenylmethane - 4,4'-diisocyanate, add it to the grease kettle, carry out saponification reaction for 30 minutes, then add 10 g of water to the grease kettle, raise the temperature to 205 °C for high - temperature refining for 15 minutes, add 326.58 g of PAO10 base oil, cool down to 110 °C, add 5.77 g of N - phenyl - α - naphthylamine and 6.19 g of barium dinonylnaphthalene sulfonate, stir evenly, and grind through a three - roll mill 3 times to form grease.

[0120] Comparative Example 2

[0121] Raw material components: 949.16 g of PAO10 (viscosity at 100 °C is 10 mm 2 / s); 79.92 g of octadecylamine; 20.11 g of cyclohexylamine; 66.01 g of diphenylmethane - 4,4'-diisocyanate; 5.77 g of N - phenyl - α - naphthylamine; 6.19 g of barium dinonylnaphthalene sulfonate; 12.73 g of tricresyl phosphate.

[0122] First, add 479.58 g of PAO10 base oil to the grease kettle. When the temperature rises to 50 °C, stop heating. Dissolve 79.92 g of octadecylamine in 81.25 g of PAO10 base oil by heating and then add it to the grease kettle. Then add 20.11 g of cyclohexylamine and stir for 10 minutes. Take 61.75 g of PAO10 base oil, heat and dissolve 66.01 g of diphenylmethane - 4,4'-diisocyanate, add it to the grease kettle, carry out saponification reaction for 30 minutes, then add 10 g of water to the grease kettle, raise the temperature to 205 °C for high - temperature refining for 15 minutes, add 326.58 g of PAO10 base oil, cool down to 110 °C, add 5.77 g of N - phenyl - α - naphthylamine, 6.19 g of barium dinonylnaphthalene sulfonate and 12.73 g of tricresyl phosphate, stir evenly, and grind through a three - roll mill 3 times to form grease.

[0123] The performance of the greases in Examples 4 - 7 and Comparative Examples 1 and 2 was evaluated. The evaluation methods and results are shown in Table 1.

[0124] As can be seen from Table 1, the polyurea - based grease of the present invention has excellent extreme - pressure and anti - wear properties and antioxidant properties, and at the same time has good colloidal stability and mechanical stability.

[0125] Table 1 Performance Evaluation of Grease

[0126]

Claims

1. Polyurea-based grease, comprising the following components: (A) Phosphate ester salt, accounting for 0.1% - 10% of the total weight of the polyurea-based grease; (B) Antioxidant, accounting for 0.1% - 10% of the total weight of the polyurea-based grease; (C) Rust inhibitor, accounting for 0.1% - 5% of the total weight of the polyurea-based grease; (D) Polyurea thickener, accounting for 1% - 30% of the total weight of the polyurea-based grease; (E) Lubricating base oil, constituting the main component of the polyurea-based grease; Wherein the phosphate ester salt includes a structural unit shown in formula (1), and at least one of the structural units shown in formula (2), formula (3) and formula (4), Among them, R1 and R2 are each independently selected from hydrogen, hydrocarbon group, substituted hydrocarbon group or heteroalkyl group; Wherein, X1 is selected from nitrogen or methylene, R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R3, R4 and R5 are each independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1; Among them, R6, R7, and R8 are each independently selected from C1-C5 hydrocarbon groups, and r3 and r4 are each independently 0 or 1; Among them, R” is selected from hydrogen or a C1-C4 hydrocarbon group, R9, R 10 and R 11 are each independently selected from C1-C5 hydrocarbon groups, and r5 and r6 are each independently 0 or 1.

2. The polyurea-based grease according to claim 1, characterized in that, In formula (1), R1 and R2 are not both hydrogen at the same time; Preferably, R1 and R2 are each independently selected from C4-C18 hydrocarbon groups, C4-C18 hydroxy-substituted hydrocarbon groups or C3-C20 heteroalkyl groups; Preferably, the heteroatom in the heteroalkyl group is at least one of O, N and S, preferably O and / or S, and more preferably S.

3. The polyurea-based grease according to claim 2, wherein, R1 and R2 are each independently selected from n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, benzyl, methylphenyl or dimethylphenyl.

4. The polyurea-based grease according to claim 1, wherein In formulas (2)-(4), R3, R6, and R9 are each independently -(CH2) a -, where a is selected from 2-5; and / or, R4, R7, R 10 each independently is -(CH2) b -, where b is 1 - 2; and / or, R5, R8, R 11 each independently is -(CH2) c -, where c is 1 - 3.

5. The polyurea-based grease according to claim 1, characterized in that, The preparation method of the phosphate ester salt includes: Contacting an acidic phosphate ester having the structure shown in formula (5) with a nitrogen-containing organic compound having a bicyclic structure to carry out a phosphate ester salt formation reaction; Wherein, R1 and R2 are each independently selected from hydrogen, a hydrocarbon group, a substituted hydrocarbon group or a heteroalkyl group; Wherein the nitrogen-containing organic compound has at least one of the structures shown in formula (6), formula (7) and formula (8), Wherein, X1 is selected from nitrogen or methylene, R and R' are each independently selected from hydrogen or a C1-C4 hydrocarbon group; R3, R4 and R5 are each independently selected from a C1-C5 hydrocarbon group, and r1 and r2 are each independently 0 or 1; Wherein, R6, R7, and R8 are each independently selected from C1-C5 hydrocarbon groups, and r3 and r4 are each independently 0 or 1; Among them, R” is selected from hydrogen or a C1-C4 hydrocarbon group, and R9, R 10 and R 11 are each independently selected from C1-C5 hydrocarbon groups, and r5 and r6 are each independently 0 or 1.

6. The polyurea-based grease according to claim 5, characterized in that In formula (5), R1 and R2 are not both hydrogen at the same time; Preferably, R1 and R2 are each independently selected from C4-C18 hydrocarbon groups, C4-C18 hydroxy-substituted hydrocarbon groups or C3-C20 heteroalkyl groups; Preferably, the heteroatom in the heteroalkyl group is at least one of O, N and S, preferably O and / or S, and more preferably S; Preferably, R1 and R2 are each independently selected from n-butyl, isobutyl, tert-butyl, n-hexyl, 2-ethylhexyl, n-octyl, 1-methylheptyl, 3,5,5-trimethylhexyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 9-octadecenyl, 9,12-octadecadienyl, 12-hydroxy-9-octadecenyl, cyclohexyl, phenyl, benzyl, methylphenyl or dimethylphenyl.

7. The polyurea-based grease according to claim 5, characterized in that, In formulas (6)-(8), R3, R6, and R9 are each independently -(CH2) a -, where a is selected from 2-5; and / or, R4, R7, R 10 each independently is -(CH2) b -, where b is 1 - 2; and / or, R5, R8, R 11 each independently is -(CH2) c -, where c is 1 - 3.

8. The polyurea-based grease according to claim 5, wherein, The molar ratio of the acidic phosphate ester to the nitrogen-containing organic compound is 1:0.1 - 10, preferably 1:0.4 - 5, and more preferably 1:0.5 - 2; Preferably, the conditions for the phosphate ester salt formation reaction include: the reaction temperature is 0 - 200°C, preferably 20 - 150°C, more preferably 60 - 120°C, and the reaction time is 0.1 - 24 h, preferably 0.5 - 12 h, more preferably 1 - 5 h.

9. The polyurea-based grease according to any one of claims 1-8, characterized in that, The antioxidant is selected from one or more of N-phenyl-α-naphthylamine, alkylated diphenylamine, shielded phenol and phenol ester; the rust inhibitor is one or more of sulfonate, imidazoline alkenyl succinate and benzotriazole; the polyurea thickener is a reaction product of organic amine and isocyanate; the lubricating base oil is selected from one or more of mineral oil, vegetable oil, ester oil and poly-α-olefin oil.

10. The preparation method of the polyurea-based grease according to any one of claims 1 to 9, comprising: Add 1 / 3 to 2 / 3 of the lubricating base oil into the grease kettle and heat up. Optionally, dissolve the organic amine and isocyanate with the lubricating base oil respectively. When the temperature in the reaction kettle rises to 40-90 °C, add the organic amine or its mixed solution with the lubricating base oil. After stirring for 5-20 minutes, add the isocyanate or its mixed solution with the lubricating base oil, carry out the saponification reaction for 10-100 minutes, then add water to the reaction system, heat up to 180-220 °C for high-temperature refining for 10-60 minutes; add the remaining lubricating base oil, cool down to 100-120 °C, add phosphate ester salt, antioxidant and rust inhibitor, stir evenly, and grind into grease through a three-roll mill.

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