Adhesive PTFE film for self-lubricating bearing coating and preparation method of adhesive PTFE film

Abstract

The invention discloses an adhesive PTFE (Polytetrafluoroethylene) film for a self-lubricating bearing coating and a preparation method of the adhesive PTFE film. The PTFE film comprises the following components in parts by mass: 15-25 parts of glass fiber powder; 5%-10% of carbon fibers; 65%-80% of suspended PTFE powder; the glass fiber powder is 200-400 meshes of glass fiber powder treated by a silane coupling agent; and the carbon fibers are 500 meshes. According to the modified PTFE film prepared through the formula and the technology, the maximum bonding strength can reach 34.3 N / cm, the use requirement of a conventional sliding self-lubricating bearing is met, the modified PTFE film can be matched with an automobile steering engine bearing, the film can be machined into different thicknesses (0.1-0.5 mm) and shapes through the turning technology, the size requirements of various bearings are met, and the application range is wide. The method has a wide industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of thin film materials technology, specifically to an adhesive PTFE film for self-lubricating bearing coatings and its preparation method. Background Technology

[0002] PTFE has extremely low surface energy and hardly adheres to other substances, making it an ideal material for non-stick coatings. The fluorine atoms in its molecular structure tightly encapsulate the carbon chains, forming a chemically inert protective layer that further enhances its non-stick properties. It also boasts a low coefficient of friction, with a dynamic friction coefficient of approximately 0.05-0.10 and a static friction coefficient even lower than the dynamic friction coefficient, making it an ideal coating material for sliding self-lubricating bearings.

[0003] However, its chemical inertness, resistance to strong acids, alkalis, and organic solvents, and the fact that its carbon chains are tightly wrapped by fluorine atoms, making it almost unreactive with any chemical substances, make its surface difficult to treat. Currently, sodium naphthalene treatment solution is used to make PTFE films bondable. This solution consists of naphthalene, metallic sodium, and tetrahydrofuran, and the treated PTFE films can meet bonding requirements. However, this process is not environmentally friendly and poses significant safety risks, necessitating the development of new alternative treatment methods. Plasma treatment is one such method. High-energy particles in the plasma (such as electrons, ions, and free radicals) undergo physical etching and chemical reactions with the PTFE surface, introducing polar groups such as hydroxyl (-OH) and carboxyl (-COOH) groups, reducing the contact angle (from 120° to 23.6°).

[0004] Non-destructive modification: The processing temperature is usually below 80℃, which does not damage the substrate, but it also has problems such as shallow processing depth and low bonding strength.

[0005] Plasma treatment requires modification of the PTFE film itself. While improving the wear resistance of the self-lubricating bearing, the plasma-treated film also needs to have higher bonding strength. Therefore, PTFE material modification and plasma treatment process methods need to be developed simultaneously to meet the comprehensive performance requirements of modified PTFE.

[0006] In summary, in view of the above-mentioned problems of the prior art, there is an urgent need to provide an adhesive PTFE film for self-lubricating bearing coating and its preparation method. Summary of the Invention

[0007] The purpose of this invention is to provide an adhesive PTFE film for self-lubricating bearing coating and its preparation method. After the process and formula are improved, the adhesive PTFE film can meet the requirements of improving the wear resistance of self-lubricating bearings, while also improving the adhesion strength of the plasma-treated film, resulting in excellent overall performance of PTFE.

[0008] The non-magnetic stainless steel produced by this method has good performance and low cost, and is suitable for manufacturing components in motors that need to avoid magnetic field interference. It also has the advantages of high strength and rust resistance.

[0009] To achieve the above objectives, the following technical solutions are used: An adhesive PTFE film for self-lubricating bearing coating, the PTFE film comprising the following components in parts by weight: 15-25 parts of glass fiber powder; Carbon fiber 5%~10%; Suspended PTFE powder 65%~80%; As a further improvement to this plan, The glass fiber powder is 200-400 mesh glass fiber powder treated with silane coupling agent.

[0010] As a further improvement to this scheme, the carbon fiber is 500 mesh.

[0011] As a further improvement to this scheme, the silane coupling agent is at least one of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane.

[0012] As a further improvement to this plan, The glass fiber powder is polyacrylonitrile-based short-cut carbon fiber with a particle size of 500 mesh, a length of 50-100 μm, and a carbon content of ≥95%.

[0013] A method for preparing an adhesive PTFE film for a self-lubricating bearing coating, characterized by comprising the following preparation steps: S1 glass fiber powder treatment: Add 200-400 mesh glass fiber powder to an ethanol solution, add 1.5-2.0% of silane coupling agent by weight of glass fiber powder, stir and react at 60-70℃ for 2-3 hours, then place in a vacuum drying oven at 80-90℃ for 4-6 hours to remove ethanol and water, and obtain silane-treated glass fiber powder. S2 Mix the suspended PTFE powder, pretreated glass fiber powder, and dispersed carbon fiber according to the formula ratio for 30-45 minutes to obtain a uniform PTFE composite powder. S4 uses the PTFE composite powder from S2 to prepare a PTFE film; S4 PTFE film was subjected to plasma treatment to obtain modified PTFE film; S5 modified PTFE film is treated with 200-mesh diamond sandblasting to obtain a self-lubricating bearing coating adhesive PTFE film with a surface roughness of Ra0.8-1.0.

[0014] As a further improvement to this plan, In surface plasma treatment processes: Plasma treatment is performed using a mixture of 30% oxygen and 70% argon.

[0015] The self-lubricating bearing coating adhesive PTFE film and its preparation method of the present invention have the following beneficial effects: 1) In this invention, the glass fiber powder, through the "bridging effect" of the silane coupling agent (one end of the silane molecule binds to the hydroxyl group on the fiber surface, and the other end forms a weak chemical bond with the PTFE molecular chain), greatly improves the interfacial bonding force with the PTFE matrix, preventing fiber shedding during friction. At the same time, its high rigidity can reduce the plastic deformation of the film. The carbon fiber, with its fine particle size of 500 mesh and high aspect ratio, is uniformly dispersed in the matrix, which can not only bear the frictional stress and reduce the wear loss of PTFE, but also synergize the self-lubricating properties of PTFE. 2) In this invention, the proportion of 65%-80% suspended PTFE powder not only retains the self-lubricating core advantage of PTFE itself, but also improves the film strength through the reinforcing effect of the reinforcing body; 3) In the preparation method of this invention, the thin film undergoes surface plasma treatment using a mixed gas of 30% oxygen and 70% argon to achieve the effect of "physical etching + chemical modification". Argon, as an inert gas, has high-energy ions that can gently etch the thin film surface, forming a uniform micron-level rough structure (avoiding excessive etching by oxygen alone that could lead to surface embrittlement). Oxygen, as a reactive gas, combines with the broken CF bonds on the PTFE surface during the etching process, directionally introducing a large number of oxygen-containing polar groups (hydroxyl and carboxyl groups), which reduces the surface contact angle and significantly improves surface hydrophilicity and adhesive compatibility. Compared to single-gas treatment, this mixed ratio results in a higher density of polar groups and a stronger bond between the modified layer and the substrate, avoiding the problem of insufficient adhesion durability caused by "physical etching only", and enabling the adhesion strength between the thin film and the metal substrate to exceed 34.3 N / cm.

[0016] 4) In the processing of this invention, the surface roughness of the PTFE film is controlled at Ra0.8-1.0μm by 200-mesh diamond sandblasting, forming a uniformly distributed micron-level pit structure. When the adhesive is applied, it will penetrate into the pits and work synergistically with the chemical bonding sites introduced by the plasma treatment to maximize the dual effect of "chemical bonding + mechanical interlocking" at the bonding interface, and the maximum bonding strength can reach 34.3 N / cm. 5) The modified PTFE film prepared by the formulation and process of the present invention not only meets the requirements of conventional sliding self-lubricating bearings, but can also be adapted to automotive steering gear bearings. The film can be processed into different thicknesses (0.1-0.5mm) and shapes through turning process to meet the size requirements of various bearings and has broad prospects for industrial application. Attached Figure Description

[0017] Figure 1 This is a product image of an adhesive PTFE film for a self-lubricating bearing coating according to the present invention.

[0018] Figure 2 This invention provides a test strip for an adhesive PTFE film product used in a self-lubricating bearing coating. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below in conjunction with embodiments and accompanying drawings: An adhesive PTFE film for self-lubricating bearing coating, the PTFE film comprising the following components in parts by weight: 15-25 parts of glass fiber powder; Carbon fiber 5%~10%; Suspended PTFE powder 65%~80%; The glass fiber powder is 200-400 mesh glass fiber powder treated with silane coupling agent.

[0020] The carbon fiber is 500 mesh.

[0021] In the following embodiments, the silane coupling agent is at least one of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane.

[0022] The glass fiber powder is polyacrylonitrile-based short-cut carbon fiber with a particle size of 500 mesh, a length of 50-100 μm, and a carbon content of ≥95%.

[0023] A method for preparing an adhesive PTFE film for a self-lubricating bearing coating, characterized by comprising the following preparation steps: S1 glass fiber powder treatment: Add 200-400 mesh glass fiber powder to an ethanol solution, add 1.5-2.0% of silane coupling agent by weight of glass fiber powder, stir and react at 60-70℃ for 2-3 hours, then place in a vacuum drying oven at 80-90℃ for 4-6 hours to remove ethanol and water, and obtain silane-treated glass fiber powder. S2 Mix the suspended PTFE powder, pretreated glass fiber powder, and dispersed carbon fiber according to the formula ratio for 30-45 minutes to obtain a uniform PTFE composite powder. S4 uses the PTFE composite powder from S2 to prepare a PTFE film; S4 PTFE film was subjected to plasma treatment to obtain modified PTFE film; S5 modified PTFE film is treated with 200-mesh diamond sandblasting to obtain a self-lubricating bearing coating adhesive PTFE film with a surface roughness of Ra0.8-1.0.

[0024] As a further improvement to this plan, In surface plasma treatment processes: Plasma treatment is performed using a mixture of 30% oxygen and 70% argon.

[0025] In the example: An adhesive PTFE film for self-lubricating bearing coating, the PTFE film comprising the following components in parts by weight: Glass fiber powder; Carbon fiber; Suspended PTFE powder; The glass fiber powder is 200-400 mesh glass fiber powder treated with silane coupling agent.

[0026] The carbon fiber is 500 mesh.

[0027] In the following examples, the silane coupling agent is γ-aminopropyltriethoxysilane.

[0028] The glass fiber powder is polyacrylonitrile-based short-cut carbon fiber with a particle size of 500 mesh, a length of 50-100 μm, and a carbon content of ≥95%.

[0029] The formulations for Examples 1-4 are shown in Table 1: As can be seen from the above embodiments and comparative examples: A mixed gas of 30% oxygen and 70% argon is used to achieve the effect of "physical etching + chemical modification". Argon, as an inert gas, provides high-energy ions that gently etch the film surface, forming a uniform micron-level rough structure (avoiding surface embrittlement caused by excessive etching with oxygen alone). Oxygen, as a reactive gas, combines with the broken CF bonds on the PTFE surface during etching, directionally introducing a large number of oxygen-containing polar groups (hydroxyl and carboxyl groups), which reduces the surface contact angle and significantly improves surface hydrophilicity and adhesive compatibility. Compared with single-gas treatment, this mixed ratio results in a higher density of polar groups and a stronger bond between the modified layer and the substrate, avoiding the insufficient adhesion durability problem caused by "physical etching only", and enabling the adhesion strength between the film and the metal substrate to exceed 34.3 N / cm.

[0030] In the processing of this invention, the surface roughness of the PTFE film is controlled at Ra0.8-1.0μm by 200-mesh diamond sandblasting, forming a uniformly distributed micron-level pit structure. When the adhesive is applied, it will penetrate into the pits and work synergistically with the chemical bonding sites introduced by the plasma treatment to maximize the dual effect of "chemical bonding + mechanical interlocking" at the bonding interface, with the maximum bonding strength reaching 34.3 N / cm. The modified PTFE film prepared by the formulation and process of this invention not only meets the requirements of conventional sliding self-lubricating bearings, but can also be adapted to automotive steering gear bearings. The film can be processed into different thicknesses (0.1-0.5 mm) and shapes through turning processes to meet the size requirements of various bearings and has broad prospects for industrial application.

[0031] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent modifications made using the present invention are within the patent protection scope of the present invention.

Claims

1. An adhesive PTFE film for self-lubricating bearing coating, characterized in that, The PTFE film comprises the following components in parts by weight: 15-25 parts of glass fiber powder; Carbon fiber 5%~10%; Suspended PTFE powder 65%~80%.

2. The adhesive PTFE film for self-lubricating bearing coating according to claim 1, characterized in that, The glass fiber powder is 200-400 mesh glass fiber powder treated with silane coupling agent.

3. The adhesive PTFE film for self-lubricating bearing coating according to claim 1, characterized in that, The carbon fiber is 500 mesh.

4. The adhesive PTFE film for self-lubricating bearing coating according to claim 1, characterized in that, The silane coupling agent is at least one of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane.

5. The adhesive PTFE film for self-lubricating bearing coating according to claim 1, characterized in that, The glass fiber powder is polyacrylonitrile-based short-cut carbon fiber with a particle size of 500 mesh, a length of 50-100 μm, and a carbon content of ≥95%.

6. A method for preparing an adhesive PTFE film for a self-lubricating bearing coating as described in any one of claims 1 to 5, characterized in that, The preparation steps include the following: S1 glass fiber powder treatment: Add 200-400 mesh glass fiber powder to an ethanol solution, add 1.5-2.0% of silane coupling agent by weight of glass fiber powder, stir and react at 60-70℃ for 2-3 hours, then place in a vacuum drying oven at 80-90℃ for 4-6 hours to remove ethanol and water, and obtain silane-treated glass fiber powder. S2 Mix the suspended PTFE powder, pretreated glass fiber powder, and dispersed carbon fiber according to the formula ratio for 30-45 minutes to obtain a uniform PTFE composite powder. S4 uses the PTFE composite powder from S2 to prepare a PTFE film; S4 PTFE film was subjected to plasma treatment to obtain modified PTFE film; S5 modified PTFE film is treated with 200-mesh diamond sandblasting to obtain a self-lubricating bearing coating adhesive PTFE film with a surface roughness of Ra0.8-1.

0.

7. The method for preparing an adhesive PTFE film for a self-lubricating bearing coating according to claim 6, characterized in that, In surface plasma treatment processes: Plasma treatment is performed using a mixture of 30% oxygen and 70% argon.

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