A high temperature chain oil detergent and a method for preparing the same

Abstract

The application belongs to the technical field of lubricating oil additives, and more particularly relates to a high-temperature chain oil cleaning dispersant and a preparation method thereof; the high-temperature chain oil cleaning dispersant comprises, by mass fraction, modified polyisobutylene sulfophosphate (A) 50-60 parts, triethanolamine (TEA) 8-12 parts, ethylene glycol distearate (EGDS) 5-8 parts, sodium dodecylbenzenesulfonate (LAS) 3-5 parts, polyethylene glycol-400 (PEG-400) 3-5 parts, and synthetic ester base oil 10-31 parts. The modified polyisobutylene sulfophosphate can be dynamically cross-linked or rearranged under high temperature or mechanical stress by introducing a silicon-oxygen bond network structure to repair intermolecular cracks and defects. The prepared cleaning dispersant significantly enhances the hydrolytic stability, low-temperature fluidity and additive compatibility of polyisobutylene sulfophosphate, thereby providing a new approach for the preparation of high-temperature chain oil cleaning dispersants.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil additive technology, and more specifically, relates to a high-temperature chain oil detergent and dispersant and its preparation method. Background Technology

[0002] Polyisobutylene thiophosphate (POT) is widely used in the chain oil industry as a detergent and dispersant with a series of significant advantages. Its molecular structure endows it with excellent chemical stability, making it highly resistant to heat, light, and ozone. Even in high-temperature environments, it maintains excellent water and airtightness, which is crucial for preventing moisture intrusion and maintaining stable operation of the lubrication system under high-temperature conditions. Simultaneously, PPT also possesses excellent dielectric properties, effectively preventing damage to chains and related equipment caused by static electricity and other factors. Chinese patent CN118599034B describes a method for synthesizing polyisobutylene thiophosphate as a detergent dispersant: In a four-necked flask, an appropriate amount of polyisobutylene is added, a spherical glass condenser is attached, and cooling water is turned on. Under nitrogen protection, the mixture is stirred and heated to 100°C. Moisture is removed by purging with ammonia (10 L / min) for 10 minutes. 120 g of phosphorus pentasulfide and 7 g of sulfur powder are added, and the mixture is stirred at 200°C for 8 hours under nitrogen protection. After the reaction is complete, an oily thiophosphate is obtained. When the flask temperature drops below 100°C, 40 g of tap water is added dropwise from above the condenser, and the mixture is stirred. The mixture is refluxed at 120°C for 8 hours, cooled to 80°C, and 350 g of xylene solvent is added to obtain a hydrolysis product solution. When the flask temperature drops below 70℃, add 600g of methanol, stir, heat to 60℃, and keep at 60-70℃ for 6 hours. Separate the upper layer for centralized processing, and continue the esterification reaction in the lower layer. Add 60g of pentaerythritol to the lower layer, reflux at 198-202℃ for 8 hours, and add 180# aromatic hydrocarbons to obtain the detergent dispersant polyisobutylene thiophosphate.

[0003] However, polyisobutylene thiophosphate (POT) also exhibits some significant performance drawbacks in practical applications. Under high temperature and humidity, its hydrolytic stability is poor, making it prone to hydrolysis, which damages its molecular structure, reduces its detergency and dispersancy, and fails to effectively inhibit the formation of sludge and carbon deposits in chain oils. At low temperatures, PPT exhibits poor low-temperature fluidity, increasing oil viscosity and hindering the rapid delivery of chain oil to lubrication points, thus affecting the normal start-up and operation of equipment. Furthermore, its compatibility with other additives is poor, making it difficult to synergize with antioxidants and anti-wear agents in high-performance chain oil formulations, thus limiting the improvement of the overall performance of chain oils. Currently, existing PPT modification technologies have failed to effectively address these issues. Therefore, there is an urgent need to develop a novel preparation method to produce a high-performance high-temperature chain oil detergency and dispersant. Summary of the Invention

[0004] The purpose of this invention is to provide a high-temperature chain oil detergent and dispersant and its preparation method, which solves the problems of poor hydrolytic stability, poor low-temperature performance and additive compatibility of existing detergents and dispersants in high-temperature chain oil applications. The prepared detergent and dispersant has good chemical stability and pressure resistance, good fluidity in low-temperature environments, and good compatibility with other additives.

[0005] This invention provides a high-temperature chain oil detergent and dispersant, comprising, by weight, the following raw materials: 50-60 parts of modified polyisobutylene thiophosphate (A), 8-12 parts of triethanolamine (TEA), 5-8 parts of ethylene glycol distearate (E GDS), 3-5 parts of sodium dodecylbenzene sulfonate (LAS), 3-5 parts of polyethylene glycol-400 (PEG-400), and 10-31 parts of synthetic ester base oil.

[0006] The preparation method of the modified polyisobutylene thiophosphate (A) includes the following steps:

[0007] S1. Polyisobutylene thiophosphate is heated to 80-100℃ under nitrogen protection, the reaction system is cooled to 60-70℃, xylene solution is added, followed by γ-glycidyl etheroxypropyltrimethoxysilane and the catalyst dibutyltin dilaurate. The temperature is raised to 85-100℃ and the reaction is carried out for 1-3 hours to obtain the crude product.

[0008] S2. The crude product obtained in S1 is diluted with ethyl acetate, washed and extracted with a low-polarity organic solvent, and then distilled under reduced pressure to obtain modified polyisobutylene thiophosphate (A).

[0009] The reaction equation for the modified polyisobutylene thiophosphate (A) is as follows:

[0010]

[0011] Table 1. Assignment of characteristic peaks in the infrared spectra of polyisobutylene thiophosphate and its modified product A.

[0012]

[0013]

[0014] The infrared spectra of raw material polyisobutylene thiophosphate and product A ( Figure 1 The comparison shows that product A is located at 1100-1000 cm⁻¹. -1 Stretching vibrations of Si-OC were observed in the range of 910-840 cm⁻¹. -1 The presence of CO stretching vibration in -CH(OH)-CH2- formed after epoxy ring opening proves the successful introduction of siloxane groups.

[0015] To further optimize the performance of modified polyisobutylene thiophosphate ester A, it was compounded with base oil, TEA, EGDS, LAS, and PEG-400. Through the formation of intermolecular hydrogen bonds, a three-dimensional cross-linked network was constructed, forming a high-temperature chain oil detergent and dispersant with high stability and excellent dispersing performance.

[0016] The preparation method of the high-temperature chain oil detergent dispersant includes the following steps:

[0017] Modified polyisobutylene thiophosphate (A) is mixed with synthetic ester base oil and ultrasonically treated at 70-80℃ for 30 minutes to fully extend the siloxane segments. TEA is added and stirred at 60-70℃ for 1-2 hours to promote hydrogen bonding crosslinking between hydroxyl groups and siloxane bonds. EGDS is added and the mixture is cooled to 50-60℃ and stirred for 40 minutes to embed the alkyl chains into the hydrophobic regions of the siloxanes. LAS and PEG-400 are added and stirred at 40-50℃ for 2-3 hours to construct an ionic-hydrogen bond composite network. Unreacted monomers are filtered through a molecular sieve (pore size 0.5-0.8 nm) to obtain the final product.

[0018] A multi-component compounding process forms an intermolecular hydrogen bond network, which is further constructed into a three-dimensional cross-linked structure through the cascade effect of hydrogen bonds. Specifically, the polar groups (hydroxyl and ether bonds) of modified polyisobutylene thiophosphate (A) form multiple hydrogen bonds with the hydroxyl groups in TEA and multiple hydroxyl groups in PEG-400. Simultaneously, the polar groups in EGDS and LAS enhance intermolecular interactions through van der Waals forces and hydrogen bonds. This three-dimensional cross-linked network achieves performance optimization through the following mechanisms: enhanced dispersion stability: the synergistic effect of the long-chain structure and hydrophobic groups of PEG-400 encapsulates contaminant particles, preventing their aggregation and precipitation; improved high-temperature performance: the long-chain stearate of EGDS and the thermally stable groups of LAS jointly inhibit oil oxidation and deposit formation at high temperatures; enhanced cleaning function: the hydrophilic-hydrophobic balanced structure of LAS effectively prevents sludge formation, and, in conjunction with the cleaning groups of A, achieves a dual cleaning effect.

[0019] Preferably, the number average molecular weight of the raw material polyisobutylene thiophosphate is 800-1300, which takes into account both flowability and dispersibility.

[0020] Preferably, in the pretreatment reaction, the raw material polyisobutylene thiophosphate is stirred for 30-40 minutes under nitrogen protection.

[0021] Preferably, the mass ratio of polyisobutylene thiophosphate to the catalyst dibutyltin dilaurate is (1300-2000):1.

[0022] Preferably, the mass ratio of polyisobutylene thiophosphate to γ-glycidyl etheroxypropyltrimethoxysilane is (3.4-5.5):1.

[0023] Preferably, the reaction temperature when adding γ-glycidoxypropyltrimethoxysilane is 90°C.

[0024] Preferably, the reaction time for adding γ-glycidoxypropyltrimethoxysilane is 2 hours.

[0025] Preferably, ethyl acetate is used for dilution in the post-treatment.

[0026] Preferably, the low-polarity organic solvent is one or more of diethyl ether, n-hexane, and cyclohexane, with diethyl ether being the most preferred.

[0027] Preferably, the solvent in the product is removed by vacuum distillation.

[0028] Preferably, the C18 alkyl chain length of the ethylene glycol distearate (EGDS) is ≥90%.

[0029] Preferably, the synthetic ester base oil is dipentaerythritol ester or trimethylolpropane ester.

[0030] Beneficial effects

[0031] (1) The γ-glycidyl etheroxypropyltrimethoxysilane used in this invention has a flexible chain structure that helps improve the low-temperature fluidity of the high-temperature chain oil detergent dispersant, so that the chain oil can still maintain good fluidity in the low-temperature environment. The silane structure on the γ-glycidyl etheroxypropyltrimethoxysilane molecule can adjust the polarity of polyisobutylene thiophosphate, making it closer to the polarity range of antioxidants and anti-wear agents, reducing interfacial tension, thereby improving compatibility with other additives, making it better integrated into the high-temperature chain oil formulation system, and providing more comprehensive and better lubrication protection for the chain.

[0032] (2) Synergistic effect of siloxane bond-hydroxyl hydrogen bond (A and TEA): The ether oxygen atom in the siloxane skeleton of modified polyisobutylene thiophosphate (A) forms a hydrogen bond with the hydrogen atom of the hydroxyl group in TEA, which enhances the adsorption stability of A on the metal surface; the amino group of TEA forms an N-type bond with the sulfonic acid group of LAS. + -SO3 - Ionic bonds form a charge-repellent layer on the metal surface, increasing the stability and corrosion resistance of chain oil;

[0033] (3) Alkyl chain-siloxane hydrophobic synergy (A and EGDS): The C18 alkyl chain of EGDS is embedded into the hydrophobic siloxane segment of A through van der Waals forces to form a "comb-like" steric structure, which prevents the aggregation of carbon deposits in the chain oil. The ether oxygen of PEG-400-400 forms hydrogen bonds with the hydroxyl group of A. At the same time, the hydroxyl group of TEA and the terminal hydroxyl group of PEG form a three-dimensional cross-linked network. The hydrogen bonds can be reversibly broken / recombined at high temperature to maintain the stability of the dispersant.

[0034] (4) Modified polyisobutylene thiophosphate introduces a silicon-oxygen bond network structure, which can dynamically crosslink or rearrange under high temperature or mechanical stress, repairing intermolecular cracks and defects. At the same time, polar molecules in the system form a dynamic network through hydrogen bonds or electrostatic interactions. These molecules can recombine in real time under high temperature or friction conditions, filling the gaps caused by stress damage to the oil. Through the dynamic molecular behavior and synergistic effect of multiple components, the overall chain oil significantly enhances its detergency, dispersibility, anti-deposition, and thermal stability, thereby effectively ensuring its performance stability and long-term effectiveness under high temperature and high load conditions. Attached Figure Description

[0035] Figure 1 The infrared spectra of the raw material polyisobutylene thiophosphate and product A of this invention are shown. Detailed Implementation

[0036] To better explain the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. The described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods. Unless otherwise specified, the materials and reagents used in the following embodiments and comparative examples are commercially available.

[0037] The γ-glycidoxypropyltrimethoxysilane was purchased from Nanjing Yudeheng Fine Chemical Co., Ltd.

[0038] The dibutyltin dilaurate was purchased from Guangzhou Haoyi New Material Technology Co., Ltd.

[0039] The triethanolamine (TEA) was purchased from Jiangsu Yida Chemical Co., Ltd.

[0040] The ethylene glycol distearate (EGDS) was purchased from Hangzhou Oil & Fat Chemical Co., Ltd.

[0041] The sodium dodecylbenzenesulfonate (LAS) was purchased from Jiangsu Youshi Chemical Co., Ltd.

[0042] The polyethylene glycol (PEG-400) was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0043] The synthetic ester base oil was purchased from Sinopec Lubricating Oil Company.

[0044] Example 1

[0045] Example 1 provides a high-temperature chain oil detergent and dispersant, which, by weight, comprises: 50 parts of modified polyisobutylene thiophosphate (A), 12 parts of triethanolamine (TEA), 8 parts of ethylene glycol distearate (EGDS), 5 parts of sodium dodecylbenzenesulfonate (LAS), 5 parts of polyethylene glycol-400 (PEG-400), and 20 parts of synthetic ester base oil.

[0046] A method for preparing a high-temperature chain oil detergent dispersant includes the following steps:

[0047] S1. 42g of polyisobutylene thiophosphate was heated to 80℃ under nitrogen protection, the reaction system was cooled to 60℃, 100mL of xylene solution, 12g of γ-glycidyl etheroxypropyltrimethoxysilane, and 0.03g of dibutyltin dilaurate catalyst were added, the temperature was raised to 85℃, and the reaction was carried out for 1 hour to obtain the crude product.

[0048] S2. The crude product obtained in S1 was diluted with ethyl acetate, washed and extracted with the low-polarity organic solvent n-hexane, and then distilled under reduced pressure to obtain modified polyisobutylene thiophosphate (A).

[0049] S3. The modified polyisobutylene thiophosphate (A) was mixed with 20g of dipentaerythritol ester and ultrasonically treated at 70°C for 30 minutes. 12g of TEA was added and stirred at 60°C for 1 hour. 8g of EGDS was added and the mixture was cooled to 50°C and stirred for 40 minutes. 5g of LAS and 5g of PEG-400 were added and stirred at 40°C for 2 hours. Unreacted monomers were filtered through a molecular sieve (pore size 0.5nm) to obtain the final product.

[0050] Example 2

[0051] Example 2 provides a high-temperature chain oil detergent and dispersant, which, by weight, comprises the following raw materials: 55 parts of modified polyisobutylene thiophosphate (A), 10 parts of triethanolamine (TEA), 8 parts of ethylene glycol distearate (EGDS), 3 parts of sodium dodecylbenzene sulfonate (LAS), 3 parts of polyethylene glycol-400 (PEG-400), and 21 parts of synthetic ester base oil;

[0052] A method for preparing a high-temperature chain oil detergent dispersant includes the following steps:

[0053] S1. 46g of polyisobutylene thiophosphate was heated to 90℃ under nitrogen protection, the reaction system was cooled to 60℃, 110mL of xylene solution, 13g of γ-glycidyl etheroxypropyltrimethoxysilane, and 0.035g of dibutyltin dilaurate catalyst were added, the temperature was raised to 90℃, and the reaction was carried out for 2 hours to obtain the crude product.

[0054] S2. The crude product obtained in S1 was diluted with ethyl acetate, washed and extracted with diethyl ether, a low-polarity organic solvent, and then distilled under reduced pressure to obtain modified polyisobutylene thiophosphate (A).

[0055] S3. The modified polyisobutylene thiophosphate (A) was mixed with 21g of dipentaerythritol ester and ultrasonically treated at 70°C for 30 minutes. 10g of TEA was added and stirred at 60°C for 1 hour. 8g of EGDS was added and the mixture was cooled to 50°C and stirred for 40 minutes. 3g of LAS and 3g of PEG-400 were added and stirred at 40°C for 2 hours. Unreacted monomers were filtered through a molecular sieve (pore size 0.5nm) to obtain the final product.

[0056] Example 3

[0057] Example 3 provides a high-temperature chain oil detergent and dispersant, which, by weight, comprises: 60 parts of modified polyisobutylene thiophosphate (A), 12 parts of triethanolamine (TEA), 5 parts of ethylene glycol distearate (EGDS), 4 parts of sodium dodecylbenzenesulfonate (LAS), 4 parts of polyethylene glycol-400 (PEG-400), and 15 parts of synthetic ester base oil.

[0058] A method for preparing a high-temperature chain oil detergent dispersant includes the following steps:

[0059] S1. 50g of polyisobutylene thiophosphate was heated to 100℃ under nitrogen protection, the reaction system was cooled to 70℃, 130mL of xylene solution, 15g of γ-glycidyl etheroxypropyltrimethoxysilane, and 0.04g of dibutyltin dilaurate catalyst were added, the temperature was raised to 100℃, and the reaction was carried out for 3 hours to obtain the crude product.

[0060] S2. The crude product obtained in S1 was diluted with ethyl acetate, washed and extracted with the low-polarity organic solvent n-hexane, and then distilled under reduced pressure to obtain modified polyisobutylene thiophosphate (A).

[0061] S3. Mix the modified polyisobutylene thiophosphate (A) with 10g of dipentaerythritol ester, sonicate at 70°C for 30 minutes, add 12g of TEA, stir at 60°C for 1 hour, add 5g of EGDS, cool to 50°C and stir for 40 minutes, add 4g of LAS and 4g of PEG-400, stir at 50°C for 3 hours, filter unreacted monomers through a molecular sieve (pore size 0.5nm) to obtain the final product.

[0062] Comparative Example 1

[0063] Comparative Example 1 provides a high-temperature chain oil detergent and dispersant, which differs from Example 1 in that the raw material includes unmodified polyisobutylene thiophosphate. The preparation method of the high-temperature chain oil detergent and dispersant differs from Example 1 in that it uses unmodified polyisobutylene thiophosphate.

[0064] Performance testing: The high-temperature chain oil detergents and dispersants obtained in Examples 1-3 and Comparative Example 1 were tested according to the items in Table 2. The test results are shown in Table 2.

[0065] Table 2. Performance test results of the high-temperature chain oil detergents and dispersants obtained in Examples 1-3 and Comparative Example 1.

[0066]

[0067]

[0068] As shown in Table 1, Comparative Example 1, using unmodified polyisobutylene thiophosphate, possesses high polarity and acidic groups, directly increasing the acid value of the final product. Especially at high temperatures, the unmodified groups are prone to side reactions or oxidation, further generating acidic substances and leading to a further increase in the acid value. Polyisobutylene thiophosphate itself is a high molecular weight substance; without modification, its molecular structure is relatively rigid, and the intermolecular interactions are strong, making it more prone to molecular aggregation at low temperatures, thus increasing the pour point of the final product. Unmodified polyisobutylene thiophosphate exhibits poor flowability at low temperatures; its rigid molecular structure and high intermolecular forces significantly increase the low-temperature dynamic viscosity of the system. The lack of sufficient dispersibility between unmodified polyisobutylene thiophosphate molecules makes it prone to forming microcrystals or aggregates at low temperatures, leading to an increase in the cold filter plugging point. Unmodified polyisobutylene thiophosphate has poor compatibility with other components in the system due to the exposure of polar groups and the lack of modification by silicon-oxygen bonds. It is prone to uneven distribution between molecules, forming tiny insoluble particles or micelles, resulting in poor solubility and increased turbidity (NTU).

[0069] The content presented above is merely a specific example of the invention in practical application and does not imply a limitation on the scope of patent protection for this invention. Any adjustments or improvements made based on the core concept of this invention, or any application of the technical solution of this invention to other related technical fields through direct reference or indirect borrowing, should be included within the scope of patent protection of this invention and protected by applicable laws.

Claims

1. A high-temperature chain oil detergent and dispersant, characterized in that, By weight, the raw materials include: 50-60 parts of modified polyisobutylene thiophosphate, 8-12 parts of triethanolamine, 5-8 parts of ethylene glycol distearate, 3-5 parts of sodium dodecylbenzene sulfonate, 3-5 parts of polyethylene glycol-400, and 10-31 parts of synthetic ester base oil. The chemical structural formula of the modified polyisobutylene thiophosphate is:

2. A method for preparing the high-temperature chain oil detergent dispersant according to claim 1, characterized in that, Includes the following steps: S1. Polyisobutylene thiophosphate is heated to 80-100℃ under nitrogen protection, the reaction system is cooled to 60-70℃, xylene solution is added, followed by γ-glycidyl etheroxypropyltrimethoxysilane and the catalyst dibutyltin dilaurate. The temperature is raised to 85-100℃ and the reaction is carried out for 1-3 hours to obtain the crude product. S2. The crude product obtained in S1 was diluted with ethyl acetate, washed and extracted with a low-polarity organic solvent, and then distilled under reduced pressure to obtain modified polyisobutylene thiophosphate. S3. Mix modified polyisobutylene thiophosphate with synthetic ester base oil, sonicate at 70-80℃ for 30 minutes, add triethanolamine, stir at 60-70℃ for 1-2 hours, add ethylene glycol distearate, cool to 50-60℃ and stir for 40 minutes, add sodium dodecylbenzenesulfonate and polyethylene glycol-400, stir at 40-50℃ for 2-3 hours, filter unreacted monomers through molecular sieve to obtain the final product.

3. The preparation method of the high-temperature chain oil detergent dispersant according to claim 2, characterized in that, The mass ratio of the polyisobutylene thiophosphate to the catalyst dibutyltin dilaurate is (1300-2000):

1.

4. The preparation method of the high-temperature chain oil detergent dispersant according to claim 2, characterized in that, The mass ratio of the polyisobutylene thiophosphate to γ-glycidyl etheroxypropyltrimethoxysilane is (3.4-5.5):

1.

5. The preparation method of the high-temperature chain oil detergent dispersant according to claim 2, characterized in that, The low-polarity organic solvent is one or more of diethyl ether, n-hexane, and cyclohexane.

6. The preparation method of the high-temperature chain oil detergent dispersant according to claim 2, characterized in that, The C18 alkyl chain length of the ethylene glycol distearate is ≥90%.

7. The preparation method of the high-temperature chain oil detergent dispersant according to claim 2, characterized in that, The synthetic ester base oil is dipentaerythritol ester or trimethylolpropane ester.

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