Synthetic method and application of anti-shearing agent for water-based dry film lubricant

Abstract

The invention relates to a method for synthesizing an anti-shearing agent for a water-based dry film lubricant, which comprises the following steps of: synthesizing block polycarbonate: performing ring-opening polymerization on cyclic carbonate and methyl-terminated polyethylene glycol under the action of a catalyst to generate the block polycarbonate; the molecular weight of the block polycarbonate prepared from the selected methoxy polyethylene glycol is 500 to 6000 g / mol. The specific method of the block polycarbonate comprises the following steps: adding methoxy polyethylene glycol and carbonate as shown in a formula II into a reactor at normal temperature, then adding a catalyst, heating to 30-80 DEG C, and reacting for 3-6 hours to obtain the block polycarbonate. Compared with an existing anti-shearing agent, the anti-shearing agent has the obvious advantages of being efficient, easy to prepare, environmentally friendly and the like.

Description

Technical Field

[0001] The present invention belongs to the field of polymer synthesis, and particularly relates to a method for synthesizing an anti-shear agent for water-based dry film lubricants and its application. Background Art

[0002] With the rapid development of industrial technologies, dry film lubricants are increasingly widely used under high loads, extreme temperatures, and harsh environmental conditions. Due to their low friction coefficient, high-temperature stability, and corrosion resistance, dry film lubricants are widely applied in fields such as aerospace, automotive manufacturing, precision machinery, and medical devices. However, under dynamic loading and high shear stress conditions, the performance of existing dry film lubricants is usually limited. In particular, the lubricating film in the water-based system is prone to breakage or detachment during the shearing process, which greatly shortens its service life in high-intensity application scenarios.

[0003] Traditional dry film lubricants mostly adopt solvent-based formulations, and their matrix materials usually use fluoropolymers, silicone resins, or polytetrafluoroethylene, etc. However, solvent-based lubricants will release a large amount of volatile organic compounds (VOCs) during production and use, posing a potential threat to the environment and human health. In recent years, with the increasingly strict environmental protection regulations, water-based dry film lubricants have gradually become a research and development hotspot. The water-based system reduces the use of organic solvents, while reducing environmental pollution, improving safety and applicability.

[0004] The key material for anti-shearing in water-based dry film lubricants is the matrix polymer. Due to the irregular arrangement of molecular segments or insufficient crosslinking degree of traditional polymers, chain breakage or lubrication failure is likely to occur under high shear conditions. Current research mostly focuses on introducing polymers with high strength and high elastic recovery ability. However, in the existing technology, the polymer synthesis methods for water-based systems have the following problems: (1) Insufficient molecular design: The structural design of polymers fails to fully consider the balance between anti-shearing performance and water-based system stability; (2) Complex synthesis process: Existing methods usually require multiple steps of reaction, with high process costs and easy generation of by-products, making it difficult to achieve large-scale industrial production. (3) Poor environmental adaptability: Some polymers have poor stability in water-based systems, resulting in reduced dispersibility during storage and application, affecting the uniformity of the lubricating film.

[0005] Therefore, there is an urgent need to develop a water-based polymer with a simple synthesis process, environmental friendliness, and excellent anti-shearing performance to improve the performance and service life of water-based dry film lubricants under dynamic loading conditions. Such polymers should have an adjustable molecular structure, capable of achieving high molecular weight and uniform molecular chain distribution, thus combining anti-shearing performance with excellent water-based dispersibility. Summary of the Invention

[0006] In view of the deficiencies of the existing technologies, the purpose of the present invention is to provide a method for synthesizing and applying an anti-shear agent for water-based dry film lubricants. By using water-based cyclic carbonates as substrates and copolymerizing them with polyethylene glycol, and controlling the degree of polymerization of carbonate groups, an efficient anti-shear agent can be prepared. This compound has high commercial application potential in fields such as precision machinery, automobile manufacturing, and medical devices.

[0007] The technical solutions to achieve the above purpose are as follows:

[0008] A method for synthesizing an anti-shear agent for water-based dry film lubricants, the steps of which are:

[0009] Synthesis of block polycarbonate: Under the action of a catalyst, cyclic carbonate and methyl-terminated polyethylene glycol undergo ring-opening polymerization to form block polycarbonate; the molecular formula of the polycarbonate is shown in formula (I):

[0010]

[0011] Among them, x and m are the degrees of polymerization of polyethylene glycol and polycarbonate respectively, and n is the number of ethoxy groups in the cyclic carbonate group. The cyclic carbonate used for synthesizing this structure is selected from the following structures:

[0012]

[0013] The molecular weight of the methoxy polyethylene glycol used for preparing block polycarbonate is 500 - 6000 g / mol.

[0014] The catalysts used for preparing polycarbonate are: NaH, KH, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene.

[0015] The specific method for block polycarbonate is: At room temperature, add methoxy polyethylene glycol and the carbonate shown in formula II to the reactor, then add the catalyst, heat to 30 - 80 °C, and after reacting for 3 - 6 h, block polycarbonate is obtained.

[0016] The application method of the above anti-shear agent for water-based dry film lubricants is to use the anti-shear agent, and the mass fraction of the anti-shear agent added to the formulation is 0.1% - 20%.

[0017] Furthermore, for the application method of the above anti-shear agent for water-based dry film lubricants, when using the anti-shear agent, the mass fraction of the anti-shear agent added to the formulation is 0.5 - 1%.

[0018] The present invention first proposes to form a uniform adhesion film layer on the substrate surface through the strong adhesion of carbonate polar groups, reducing the shear effect during the friction process. By adopting the synthetic route of ring-opening polymerization, the preparation of large-scale shear-resistant agents with carbonate groups is achieved in one step. The reaction has high selectivity and yield. The product can be applied to the aqueous dry film agent formulation without purification.

[0019] Based on practical applications, the present invention discovers and solves problems, and uses aqueous cyclic carbonate monomers to prepare dry film lubricants. This preparation method is proposed for the first time and applied to the application of high-value-added cyclic carbonates.

[0020] The beneficial effects of the present invention are as follows: The technical solution of the present invention has the following beneficial effects:

[0021] (1) Through the above synthetic method, the present invention can obtain high-value-added block polycarbonates for anti-shear applications of dry film lubricants. Compared with the anti-shear agents in the existing dry film lubrication formulations, it has the characteristics of high anti-shear, simple synthesis, and wide application, and has great commercial application prospects in fields such as automobile manufacturing and medical devices.

[0022] (2) The preparation method of the present invention is used to prepare block polycarbonates. At present, there is no corresponding material applied to the manufacture of dry film lubricant formulations. Compared with the known technologies, the present invention develops a lubricant additive with carbonate groups.

[0023] (3) The cyclic carbonate used in the present invention has a simple synthesis method, wide raw material sources, and does not require the use of solvents, which is beneficial to reducing production costs and has obvious economic advantages.

[0024] In summary, compared with the existing anti-shear agents, the present invention has obvious advantages such as high efficiency, easy preparation, and environmental friendliness. Description of the Drawings

[0025] Figure 1 、1H NMR spectrum of the block polycarbonate product in Example 1

[0026] Figure 2 、1H NMR spectrum of the block polycarbonate product in Example 2.

[0027] Figure 3 、1H NMR spectrum of the block polycarbonate product in Example 3.

[0028] Figure 4 、Effect of Formulation 1 after coating and drying the dry film lubricant on the leather surface.

[0029] Figure 5 、Effect of Formulation 2 after coating and drying the dry film lubricant on the leather surface. Detailed Embodiments

[0030] The present invention can be further illustrated by the following examples, which are for illustrative purposes and not intended to limit the invention. Any ordinary person skilled in the art can understand that these examples do not limit the present invention in any way and can make appropriate modifications and data transformations without departing from the essence and scope of the present invention.

[0031] In the examples, the nuclear magnetic resonance hydrogen spectrum was measured using a Bruker Ascend TM-400 nuclear magnetic resonance hydrogen spectrometer from Bruker Corporation, and the deuterated reagent used was deuterated chloroform (CDCl3).

[0032] All raw materials used in the following examples were purchased from Alfa Aesar.

[0033] The cyclic carbonate used in the examples has the following structure:

[0034]

[0035] Example 1:

[0036] The synthesis method of the shear-resistant agent for the water-based dry film lubricant in this example is as follows: The reaction flask was subjected to water and oxygen removal operations, and 0.1 mmol KH, 1 mmol of 2MC numbered 1, and 0.083 mmol of methoxypolyethylene glycol with a molecular weight of 600 were added under an inert gas atmosphere. It was placed in an oil bath at 30 °C and reacted for 3 - 5 hours. After the reaction, it was quenched with an excess of benzoic acid. The resulting product was a colorless clear liquid, without the need for a purification step, and the yield was 98%. The hydrogen spectrum of the crude product is as Figure 1 shown, (nuclear magnetic resonance hydrogen spectrum, 400 Hz, CDCl3).

[0037] Example 2:

[0038] The synthesis method of the shear-resistant agent for the water-based dry film lubricant in the example is as follows: The reaction flask was subjected to water and oxygen removal operations, and 0.1 mmol NaH, 3MC numbered 2, and 0.05 mmol of methoxypolyethylene glycol with a molecular weight of 1000 were added under an inert gas atmosphere. It was placed in an oil bath at 50 °C and reacted for 3 - 4 hours. After the reaction, it was quenched with an excess of benzoic acid. The resulting product was a colorless clear liquid, without the need for a purification step, and the yield was 96.5%. The hydrogen spectrum of the crude product is as Figure 2 shown, (nuclear magnetic resonance hydrogen spectrum, 400 Hz, CDCl3).

[0039] Example 3:

[0040] The synthesis method of the anti-shearing agent for water-based dry film lubricant in this example comprises the following steps: Carry out water and oxygen removal operations on the reaction flask, add 0.1 mmol of 1,8-diazabicyclo[5.4.0]undec-7-ene, 4MC numbered 3, and 0.025 mmol of methoxypolyethylene glycol with a molecular weight of 2000 under the condition of introducing inert gas. Place it in an oil bath at 80 °C and react for 3 hours. After the reaction, quench with excessive benzoic acid. The obtained product is a colorless clear liquid, without the need for a purification step, and the yield is 98%. The hydrogen spectrum of the crude product is as shown in Figure 3 shown, (nuclear magnetic resonance hydrogen spectrum, 400 Hz, CDCl3).

[0041] Example 4:

[0042] The synthesis method of the anti-shearing agent for water-based dry film lubricant in this example comprises the following steps: Carry out water and oxygen removal operations on the reaction flask, add 0.1 mmol of 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1 mmol of 3MC numbered 2, and 0.05 mmol of methoxypolyethylene glycol with a molecular weight of 1000 under the condition of introducing inert gas. Place it in an oil bath at 40 °C and react for 4 hours. After the reaction, quench with excessive benzoic acid. The obtained product is a colorless clear liquid, without the need for a purification step, and the yield is 98%.

[0043] Example 5:

[0044] The synthesis method of the anti-shearing agent for water-based dry film lubricant in this example comprises the following steps: Carry out water and oxygen removal operations on the reaction flask, add 0.1 mmol of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1 mmol of 2MC numbered 1, and 0.008 mmol of methoxypolyethylene glycol with a molecular weight of 6000 under the condition of introducing inert gas, and place it in an oil bath at 50 °C and react for 5 hours. After the reaction, quench with excessive benzoic acid. The obtained product is a white solid, without the need for a purification step, and the yield is 98%.

[0045] Examples of the application of the anti-shearing agent for water-based dry film lubricant are as follows:

[0046] Formulation 1:

[0047] In this formulation, each component is uniformly mixed by mass percentage as follows: 89 parts of deionized water, 5 parts of polyethylene glycol (Mw2000), 5 parts of polytetrafluoroethylene, 0.5 part of defoamer, and 0.5 part of anti-shear agent. Referring to the standards of GB / T2423.4-2008 and GB / T21196-2007, the durability performance of this lubricant was tested and compared with the formulation without the anti-shear agent. The product in Formulation 1 was subjected to 100,000 friction cycles, and the friction reduction was 82.5%; in the comparative example, without the anti-shear agent, after 100,000 friction cycles, the friction reduction was 30.6%. Compared with the comparative example, the friction reduction effect of this product is obvious. Figure 4 This is the effect after drying the dry film lubricant coated on the leather surface in Formulation 1.

[0048] Formulation 2:

[0049] In this formulation, each component is uniformly mixed by mass percentage as follows: 79 parts of deionized water, 15 parts of polyethylene glycol (Mw2000), 5 parts of polytetrafluoroethylene, 0.9 part of defoamer, and 0.1 part of anti-shear agent. Referring to the standards of GB / T2423.4-2008 and GB / T21196-2007, the durability performance of this lubricant was tested and compared with the formulation without the anti-shear agent. The product in Formulation 2 was subjected to 50,000 friction cycles, and the friction reduction was 73.2%; in the comparative example, without the anti-shear agent, after 50,000 friction cycles, the friction reduction was 8.3%. Compared with the comparative example, the friction reduction effect of this product is obvious. Figure 5 This is the effect after drying the dry film lubricant coated on the leather surface in Formulation 2.

[0050] Formulation 3:

[0051] In this formulation, each component is uniformly mixed by mass percentage as follows: 80 parts of deionized water, 10 parts of polyethylene glycol (Mw2000), 8 parts of polytetrafluoroethylene, 1 part of defoamer, and 1 part of anti-shear agent. Referring to the standards of GB / T2423.4-2008 and GB / T21196-2007, the durability performance of the lubricant was tested and compared with the formulation without the anti-shear agent. The product in Formulation 3 was subjected to 200,000 friction cycles, and the friction reduction was 82.2%; without the anti-shear agent, after 200,000 friction cycles, the friction reduction was 48.3%. Compared with the comparative example, the friction reduction effect of this product is obvious.

[0052] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A synthesis method of an anti-shear agent for water-based dry film lubricants, characterized in that: The steps of the synthesis method are as follows: Synthesis of block polycarbonate: Ring carbonate and methyl-capped polyethylene glycol are subjected to ring-opening polymerization under the action of a catalyst to generate block polycarbonate; the molecular formula of the polycarbonate is shown in formula (I): x and m are the degrees of polymerization of polyethylene glycol and polycarbonate respectively, and n is the number of ethoxy groups contained in the ring carbonate group. The ring carbonate used for synthesizing this structure is selected from the following structures: The molecular weight of the methoxypolyethylene glycol used for preparing the block polycarbonate is 500-6000 g / mol.

2. The synthesis method of the anti-shearing agent for the aqueous dry film lubricant according to claim 1, characterized in that: The catalyst is: NaH or KH or 1,8-diazabicyclo[5.4.0]undec-7-ene or 1,5,7-triazabicyclo[4.4.0]dec-5-ene or 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene.

3. The synthesis method of the anti-shear agent for the water-based dry film lubricant according to claim 1, characterized in that: The specific method for the block polycarbonate shown is as follows: At room temperature, methoxypolyethylene glycol and the carbonate shown in formula II are added to a reactor, and then a catalyst is added. After heating to 30-80 °C and reacting for 3-6 h, block polycarbonate is obtained.

4. An application method of an anti-shear agent for water-based dry film lubricants, characterized in that: When using the anti-shear agent, the mass fraction of the anti-shear agent added to the formulation is 0.1%-20%.

5. An application method of an anti-shearing agent for water-based dry film lubricant, characterized in that: When using the anti-shear agent, the mass fraction of the anti-shear agent added to the formulation is 0.5-1%.

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