Axle hub oil seal product and preparation method thereof

Abstract

The invention relates to the technical field of oil seal materials, in particular to an axle wheel hub oil seal product and a preparation method thereof. The preparation raw materials thereof at least include, by weight, 80-120 parts of a fluoropolymer matrix, 1-3 parts of a plasticizer, 4-6 parts of a wear-resistant material, 3-6 parts of a lubricating dispersant, 15-30 parts of a filler, 4-6 parts of carbon black, 1-3 parts of an internal mold release agent, 1.5-3 parts of a vulcanizing agent, 0.1-1 parts of a cross-linking aid, and 0.4-1 parts of an accelerator. By adopting a specific fluoropolymer matrix to interact with the plasticizer, the solid raw materials in the system are fully dispersed, so that the obtained axle wheel hub oil seal product can achieve a wide temperature range of low temperature resistance of 45°C and high temperature resistance of 150°C, while ensuring wear resistance and pressure resistance under high speed conditions, thereby meeting stringent market demands.

Description

Technical Field

[0001] The invention relates to the technical field of oil seal materials, in particular to an axle hub oil seal product and a preparation method thereof. Background Art

[0002] Oil seal products include fluid sealing materials and non-fluid sealing materials. The sealing effect is directly related to the quality of the oil seal products, and the quality of the oil seal products directly affects the work and production efficiency of the mechanical equipment itself.

[0003] There are many types of oil seal products on the market, but different devices or fields have different requirements for oil seal products, and there are certain differences in the performance of oil seal products. Therefore, the overall formula design of oil seal products will be fundamentally different under different requirements. For example, China's patent application CN106519525A discloses an engine oil seal rubber material and its preparation method, which specifically uses acrylate rubber, styrene-butadiene rubber, high wear-resistant white carbon black and other raw materials to prepare an engine oil seal material with good oil resistance, heat resistance and air tightness. China's patent application CN104086718A discloses a rubber material for automobile oil seals, which specifically uses methyl acrylate, ethyl acrylate, nitrile rubber, common rubber, white carbon black, talcum powder, etc. as raw materials, with the purpose of providing an automobile oil seal product with good oil resistance, heat resistance, corrosion resistance and weather resistance. However, when used in axle hubs, under high speed and high pressure conditions, there are problems such as poor wear resistance of the oil seal, easy tearing of the lip, and local debonding between the skeleton and the rubber material.

[0004] Therefore, it is a direct market demand in this field to provide an axle hub oil seal product to overcome its defects of being unable to meet the requirements of low temperature resistance of -45°C and high temperature resistance of 150°C over a wide temperature range while ensuring wear resistance and pressure resistance under high speed conditions. Summary of the invention

[0005] On the one hand, the present invention provides an axle wheel hub oil seal product, and its preparation raw materials include at least, by weight: 80-120 parts of fluorine-containing polymer matrix, 1-3 parts of plasticizer, 4-6 parts of wear-resistant material, 3-6 parts of lubricating dispersant, 15-30 parts of filler, 4-6 parts of carbon black, 1-3 parts of internal release agent, 1.5-3 parts of vulcanizer, 0.1-1 parts of cross-linking agent, and 0.4-1 parts of accelerator.

[0006] As a preferred technical solution, the fluorine-containing polymer matrix is ​​at least one of polytetrafluoroethylene, polyvinylidene fluoride, fluororubber raw rubber, and perfluoroether rubber compound; as a preferred technical solution, the fluorine-containing polymer matrix is ​​a combination of fluororubber raw rubber and perfluoroether rubber compound; preferably, the mass ratio of the fluororubber raw rubber and the perfluoroether rubber compound is (1-4):1. Preferably, the fluororubber raw rubber is at least one of ternary fluororubber raw rubber and binary fluororubber raw rubber; preferably, the fluororubber raw rubber includes ternary fluororubber raw rubber and binary fluororubber raw rubber; the mass ratio of the ternary fluororubber raw rubber and the binary fluororubber raw rubber is 1:(0.8-1.2). Preferably, the Mooney viscosity [ML (1+10), 121°C] of the ternary fluororubber raw rubber is 61-100; the Mooney viscosity [ML (1+10), 121°C] of the binary fluororubber raw rubber is 85-145; the model of the ternary fluororubber raw rubber is FE2463, and the model of the binary fluororubber raw rubber is FE2603, both of which are sourced from Fuzhou Taipuda New Materials Co., Ltd.

[0007] As a preferred technical solution, the perfluoroether rubber compound is at least one of FF2870, FF2875, FF2875L, and FF2885; preferably, the perfluoroether rubber compound is FF2875, which is sourced from Fuzhou Taipuda New Materials Co., Ltd.

[0008] Based on the system of the present invention, by selecting fluororubber raw rubber and perfluoroether rubber compound rubber with a mass ratio of (1-4):1 as the fluoropolymer matrix, and under the joint action of the wear-resistant material, filler and carbon black in the system, the wear resistance and pressure resistance of the product at high speed are significantly improved on the basis of ensuring the physical and mechanical properties of the product, and the high temperature resistance and oil resistance of the product are improved, so as to achieve the long-lasting and effective sealing performance of the product. Further, by selecting a ternary fluororubber raw rubber with a Mooney viscosity [ML (1+10), 121°C] of 61-10, a binary fluororubber raw rubber with a Mooney viscosity [ML (1+10), 121°C] of 85-145, and a FF2875 perfluoroether rubber compound rubber, the high temperature resistance and wear resistance of the product at high speed are significantly improved, so that the product has a long-lasting and effective sealing performance.

[0009] As a preferred technical solution, the wear-resistant material is carbon nanotubes;

[0010] As a preferred technical solution, the filler is at least one of diatomaceous earth, talc, organic bentonite and attapulgite; preferably, the filler is a combination of talc, organic bentonite and attapulgite; preferably, the mass ratio of the talc, organic bentonite and attapulgite is 1:(3-5):(1-3). Based on the system of the present invention, by introducing talc, organic bentonite and attapulgite in a mass ratio of 1:(3-5):(1-3), under the action of the lubricating dispersant in the system, they are uniformly dispersed in the mixed polymer matrix of fluororubber raw rubber and perfluoroether rubber compound. During the vulcanization process, talc, organic bentonite and attapulgite are easily peeled off into nano-scale structures, which play an effective nano-enhancement role on the polymer matrix. At the same time, under the joint action of carbon black and wear-resistant materials in the system, the tensile strength and tear resistance of the product are effectively improved.

[0011] As a preferred technical solution, the plasticizer is at least one of a synthetic ester plasticizer, a diester plasticizer, and a polyether and polyester mixed plasticizer. Preferably, the plasticizer is at least one of TP-90B, TP-95, TP-759, AW1, WB300A, KW400, and KW600; preferably, the plasticizer is a combination of KW400, TP-759, and TP-95; the mass ratio of KW400, TP-759, and TP-95 is 1:(1.5-6):(1-2); TP-759 and TP-95 are Rohm and Haas plasticizers, and KW400 comes from Dalian Aosen Technology Co., Ltd. Based on the fluororubber raw rubber and perfluoroether rubber mixed rubber used in the system of the present invention, KW400, TP-759, and TP-95 are introduced in a mass ratio of 1: (1.5-6): (1-2). On the one hand, the prepared axle wheel hub oil seal product has excellent performance retention ability after heat aging and low-temperature flexibility, and the product is suitable for use under a wide temperature range of -45°C and 150°C. The inventor analyzed that the reason may be that at this mass ratio, KW400, TP-759, and TP-95 have a synergistic effect, reducing the intermolecular force of fluororubber raw rubber and perfluoroether rubber mixed rubber, and improving the applicable temperature range of the oil seal product after vulcanization. In addition, although the introduction of synthetic ester plasticizer KW400 can improve the low-temperature flexural properties of the product to a certain extent, it is easily soluble in aliphatic aromatic hydrocarbons. During the research process, the inventors unexpectedly discovered that the introduction of polyether and polyester mixed plasticizer TP-759 and diester plasticizer TP-95 at the same time as KW400, and the mass ratio of KW400, TP-759, and TP-95 is controlled to be 1: (1.5-6): (1-2), so as to avoid KW400 from seeping out of the vulcanized product, thereby avoiding the embrittlement and shrinkage of the vulcanized product.

[0012] As a preferred technical solution, the vulcanizing agent is at least one of dicumyl peroxide, benzoyl peroxide, and 2,4-benzoyl peroxide; preferably, the vulcanizing agent is benzoyl peroxide.

[0013] As a preferred technical solution, the auxiliary crosslinking agent is triallyl isocyanurate. Based on the system of the present invention, by using 1.5-3 parts by weight of benzoyl peroxide as a vulcanizing agent, under the synergistic effect of 0.1-1 parts by weight of triallyl isocyanurate, the fluoropolymer matrix in the system is moderately crosslinked, ensuring the elasticity and strength of the axle hub oil seal product. In addition, triallyl isocyanurate also forms a good wear-resistant reinforcement system with the carbon black, wear-resistant materials and fillers in the system, effectively improving the wear resistance and pressure resistance of the product under high speed conditions. If the content of the vulcanizing agent and the auxiliary crosslinking agent is too high, the decomposition products of the unreacted products will cause the fluoropolymer to decompose and rearrange, reducing the heat-resistant air aging performance and heat-resistant compression resistance of the product.

[0014] As a preferred technical solution, the lubricating dispersant is at least one of oleamide, stearic acid, calcium stearate, stearic acid, and octyl stearate; preferably, the lubricating dispersant is a combination of octyl stearate and stearic acid. The mass ratio of octyl stearate to stearic acid is 1: (1.5-6). By introducing octyl stearate and stearic acid in a mass ratio of 1: (1.5-6) ​​as a lubricating dispersant, the uniform dispersion performance of the solid raw materials in the system is improved, the processing stability and processing efficiency of the system are improved, and the product quality is guaranteed.

[0015] As a preferred technical solution, the internal mold release agent is at least one of zinc stearate, ethylene bis stearamide, stearic acid amide, and pentaerythritol stearate; preferably, the internal mold release agent is a combination of zinc stearate and ethylene bis stearamide; preferably, the mass ratio of zinc stearate and ethylene bis stearamide is (0.8-1.2): (2-4). Based on the system of the present invention, zinc stearate and ethylene bis stearamide in a mass ratio of (0.8-1.2): (2-4) are introduced as internal mold release agents to improve the melt flowability of the fluorinated polymer matrix, improve work efficiency, and make the axle wheel hub oil seal product smooth and shiny. At the same time, the lubricating dispersant in the synergistic system effectively improves the uniform dispersion of the solid raw materials in the system, thereby improving the rubber particle extrusion, processing and vulcanization performance.

[0016] As a preferred technical solution, the accelerator is at least one of 2,2'-dibenzothiazole disulfide, 1,3-diphenylguanidine, di-o-tolylguanidine, vinyl thiourea, and N-cyclohexyl-2-benzothiazole sulfenamide; preferably, the accelerator is N-cyclohexyl-2-benzothiazole sulfenamide and 1,3-diphenylguanidine; the mass ratio of N-cyclohexyl-2-benzothiazole sulfenamide and 1,3-diphenylguanidine is (1-2): 0.5.

[0017] As a preferred technical solution, the carbon black is at least one of N550, N774, and N990.

[0018] Another aspect of the present invention provides a method for preparing an axle hub oil seal product, comprising at least the following steps:

[0019] (1) putting the fluorine-containing polymer matrix into an internal mixer for premixing to obtain a fluorine-containing polymer premix;

[0020] (2) adding an internal mold release agent, a wear-resistant material and a lubricating dispersant to the fluorine-containing polymer premix in parts by weight, and mixing to obtain a mixture A;

[0021] (3) adding a plasticizer, a filler and carbon black to mixture A according to weight, and kneading to obtain mixture B;

[0022] (4) After the mixture B is cooled to a temperature, a vulcanizing agent, a co-crosslinking agent and an accelerator are added, and vulcanization treatment is performed to obtain the product.

[0023] As a preferred technical solution, the pre-mixing temperature is 110-130°C; the mixing temperature is 110-130°C.

[0024] Beneficial Effects

[0025] 1. The present invention provides an axle hub oil seal product. By using a specific fluorine-containing polymer matrix to interact with a plasticizer, the solid raw materials in the system are fully dispersed, so that the obtained axle hub oil seal product can achieve a wide temperature range of resistance to low temperatures of -45°C and high temperatures of 150°C, while ensuring wear resistance and pressure resistance under high speed conditions, thereby meeting stringent market demands.

[0026] 2. The present invention selects fluororubber raw rubber and perfluoroether rubber mixed rubber in a mass ratio of (1-4): 1 as the fluoropolymer matrix, and under the joint action of wear-resistant materials, fillers and carbon black in the system, on the basis of ensuring the physical and mechanical properties of the product, significantly improves the wear resistance and pressure resistance of the product at high speed, and at the same time improves the high temperature resistance and oil resistance of the product, thereby achieving long-lasting and effective sealing performance of the product.

[0027] 3. Based on the system of the present invention, by introducing talcum powder, organic bentonite and attapulgite in a mass ratio of 1:(3-5):(1-3), under the action of the lubricating dispersant in the system, the carbon black and wear-resistant materials in the system are synergistically used to effectively improve the tensile strength and tear resistance of the product.

[0028] 4. Based on the fluororubber raw rubber and perfluoroether rubber mixed rubber used in the system of the present invention, KW400, TP-759 and TP-95 are introduced in a mass ratio of 1-3):(4-6):(1-2), so that the prepared axle wheel hub oil seal product has excellent performance retention ability after heat aging and low-temperature flexibility. The product is suitable for use in a wide temperature range of low temperature resistance of -45°C and high temperature resistance of 150°C. DETAILED DESCRIPTION

[0029] Example 1

[0030] Embodiment 1 of the present invention provides an axle hub oil seal product, wherein the raw materials for its preparation include, by weight: 100 parts of a fluorine-containing polymer matrix, 1.5 parts of a plasticizer, 5 parts of a wear-resistant material, 5 parts of a lubricating dispersant, 20 parts of a filler, 5 parts of carbon black, 1.5 parts of an internal release agent, 1.8 parts of a vulcanizing agent, 0.5 parts of a cross-linking aid, and 0.6 parts of an accelerator.

[0031] The fluorine-containing polymer matrix is ​​a combination of fluororubber raw rubber and perfluoroether rubber mixed rubber; the mass ratio of the fluororubber raw rubber to the perfluoroether rubber mixed rubber is 3:2. The fluororubber raw rubber includes ternary fluororubber raw rubber and binary fluororubber raw rubber; the mass ratio of the ternary fluororubber raw rubber to the binary fluororubber raw rubber is 1:1. The model of the ternary fluororubber raw rubber is FE2463, and the model of the binary fluororubber raw rubber is FE2603, both of which are from Fuzhou Taipuda New Materials Co., Ltd.

[0032] The perfluoroether rubber compound is FF2875, which comes from Fuzhou Taipuda New Materials Co., Ltd.

[0033] The wear-resistant material is carbon nanotubes; the carbon nanotubes are industrial-grade hydroxylated multi-walled carbon nanotubes, the particle size of the industrial-grade hydroxylated multi-walled carbon nanotubes is 50 nm, and the carbon nanotubes are sourced from Nanjing Xianfeng Nanomaterials Technology Co., Ltd.

[0034] The filler is a combination of talcum powder, organic bentonite and attapulgite; the mass ratio of the talcum powder, organic bentonite and attapulgite is 1:4:2.

[0035] The plasticizer is a combination of KW400, TP-759 and TP-95; the mass ratio of KW400, TP-759 and TP-95 is 2:5:1.5; the TP-759 and TP-95 are Rohm and Haas plasticizers, and the KW400 comes from Dalian Aosen Technology Co., Ltd.

[0036] The vulcanizing agent is benzoyl peroxide.

[0037] The auxiliary cross-linking agent is triallyl isocyanurate.

[0038] The lubricating dispersant is a combination of octyl stearate and stearic acid, and the mass ratio of octyl stearate to stearic acid is 2:5.

[0039] The internal mold release agent is a combination of zinc stearate and ethylene bisstearamide; the mass ratio of zinc stearate to ethylene bisstearamide is 1:3.

[0040] The accelerator is N-cyclohexyl-2-benzothiazole sulfonamide and 1,3-diphenylguanidine; the mass ratio of the N-cyclohexyl-2-benzothiazole sulfonamide and 1,3-diphenylguanidine is 1.5:0.5.

[0041] The carbon black is N550, which comes from Cabot.

[0042] Embodiment 1 of the present invention provides a method for preparing an axle hub oil seal product, comprising the following steps:

[0043] (4) placing the fluorinated polymer matrix into an internal mixer for premixing for 3 minutes to obtain a fluorinated polymer premix;

[0044] (5) adding an internal mold release agent, a wear-resistant material and a lubricating dispersant to the fluorine-containing polymer premix according to parts by weight, and mixing for 3 minutes to obtain a mixture A;

[0045] (6) Adding plasticizer, filler and carbon black to mixture A according to weight, and kneading for 3 minutes to obtain mixture B;

[0046] (4) After cooling the mixture B to 65° C., a vulcanizing agent, a co-crosslinking agent and an accelerator are added, and the mixture is vulcanized for 30 minutes.

[0047] The pre-mixing temperature is 120°C; the mixing temperature is 120°C.

[0048] Example 2

[0049] Embodiment 2 of the present invention provides an axle wheel hub oil seal product and a preparation method thereof. The specific implementation method is the same as that of Embodiment 1, except that, measured by weight, the raw materials for preparing the product include: 120 parts of fluorine-containing polymer matrix, 2 parts of plasticizer, 6 parts of wear-resistant material, 6 parts of lubricating dispersant, 25 parts of filler, 5 parts of carbon black, 1.8 parts of internal release agent, 2 parts of vulcanizing agent, 0.6 parts of cross-linking agent, and 0.6 parts of accelerator; the mass ratio of the fluororubber raw rubber and the perfluoroether rubber compound is 4:3.

[0050] Example 3

[0051] Embodiment 3 of the present invention provides an axle wheel hub oil seal product and a preparation method thereof. The specific implementation method is the same as that of Embodiment 1, except that, measured by weight, the raw materials for preparing the product include: 80 parts of fluorine-containing polymer matrix, 1.5 parts of plasticizer, 4 parts of wear-resistant material, 4 parts of lubricating dispersant, 15 parts of filler, 5 parts of carbon black, 1.2 parts of internal release agent, 1.5 parts of vulcanizing agent, 0.4 parts of cross-linking agent, and 0.5 parts of accelerator; the mass ratio of the fluororubber raw rubber and the perfluoroether rubber compound is 2:1.

[0052] Comparative Example 1

[0053] Comparative Example 1 of the present invention provides an axle wheel hub oil seal product and a preparation method thereof, and its specific implementation method is the same as that of Example 1, except that the fluorine-containing polymer matrix is ​​a ternary fluororubber raw rubber, and the model of the ternary fluororubber raw rubber is FE2461, which is sourced from Fuzhou Taipuda New Materials Co., Ltd.

[0054] Comparative Example 2

[0055] Comparative Example 2 of the present invention provides an axle hub oil seal product, and its specific implementation method is the same as that of Example 1, except that the mass ratio of the fluororubber raw rubber to the perfluoroether rubber mixed rubber is 1:5.

[0056] Comparative Example 3

[0057] Comparative Example 3 of the present invention provides an axle hub oil seal product, and its specific implementation manner is the same as that of Example 1, except that the plasticizer is KW400.

[0058] Comparative Example 4

[0059] Comparative Example 4 of the present invention provides an axle hub oil seal product, and its specific implementation manner is the same as that of Example 1, except that the plasticizer is TP-759.

[0060] Comparative Example 5

[0061] Comparative Example 5 of the present invention provides an axle hub oil seal product, and its specific implementation is the same as that of Example 1, except that the filler is talcum powder.

[0062] Performance Testing Methods

[0063] Performance Testing Methods

[0064] (1) Low temperature resistance: The axle hub oil seal products prepared in the examples and comparative examples were placed at -45°C for 3 min using a low temperature brittleness tester and then subjected to an impact test. If the product was not broken or cracked, the low temperature resistance was recorded as "qualified"; if the product was broken or cracked, the low temperature resistance was recorded as "unqualified". The results are shown in Table 1.

[0065] (2) High temperature resistance: The axle hub oil seal products prepared in the examples and comparative examples were placed in a high temperature box at 150°C for 70 hours, taken out, cooled to room temperature, and subjected to a tensile test using a tensile testing machine. If the tensile strength of the product was ≥10 MPa and the elongation was ≥150%, the high temperature resistance was recorded as "qualified"; if the tensile strength of the product was <10 MPa or the elongation was <150%, the high temperature resistance was recorded as "unqualified". The results are shown in Table 1.

[0066] (3) High-speed wear resistance: The axle hub oil seal products obtained in the embodiments and comparative examples were subjected to a simulated oil sealing test on a bench test bench with a rotation speed set at 3000 rpm. If the product did not leak oil after a running time of ≥1000 h, the high-speed wear resistance was recorded as "qualified"; if the product leaked oil after a running time of <1000 h, the high-speed wear resistance was recorded as "unqualified". The results are shown in Table 1.

[0067] (4) With reference to the national standard GB / T528, the tensile strength and elongation at break of the axle hub oil seal products obtained in the embodiments of the present invention and the comparative examples were measured. The results are shown in Table 1.

[0068] (5) Referring to the national standard GB / T529, the tear strength of the axle hub oil seal products obtained in the examples of the present invention and the comparative examples was measured. The results are shown in Table 1.

[0069] Table 1

[0070]

Claims

1. A vehicle axle hub oil seal product, characterized in that: The raw materials for its preparation include at least 80-120 parts by weight of fluorine-containing polymer matrix, 1-3 parts of plasticizer, 4-6 parts of wear-resistant material, 3-6 parts of lubricating dispersant, 15-30 parts of filler, 4-6 parts of carbon black, 1-3 parts of internal mold release agent, 1.5-3 parts of vulcanizing agent, 0.1-1 parts of cross-linking agent, and 0.4-1 parts of accelerator; the fluorine-containing polymer matrix is ​​a combination of fluororubber raw rubber and perfluoroether rubber mixed rubber, the mass ratio of the fluororubber raw rubber and the perfluoroether rubber mixed rubber is (1-4):1, the fluororubber raw rubber includes ternary fluororubber raw rubber and binary fluororubber raw rubber; the mass ratio of the ternary fluororubber raw rubber and the binary fluororubber raw rubber is 1:(0.8- 1.2), the Mooney viscosity of the ternary fluororubber raw rubber is 61-100; the Mooney viscosity of the binary fluororubber raw rubber is 85-145, and the perfluoroether rubber compound is FF2875; the filler is a combination of talcum powder, organic bentonite and attapulgite, and the mass ratio of the talcum powder, organic bentonite and attapulgite is 1: (3-5): (1-3); the plasticizer is a combination of KW400, TP-759 and TP-95; the mass ratio of KW400, TP-759 and TP-95 is 1: (1.5-6): (1-2); the vulcanizing agent is benzoyl peroxide, and the co-crosslinking agent is triallyl isocyanurate.

2. The axle hub oil seal product according to claim 1, characterized in that: The lubricating dispersant is at least one of oleamide, calcium stearate, stearic acid, and octyl stearate.

3. The axle hub oil seal product according to claim 2, characterized in that: The internal mold release agent is at least one of zinc stearate, ethylene bis stearamide, stearic acid amide, and pentaerythritol stearate.

4. A method for preparing an axle hub oil seal product according to any one of claims 1 to 3, characterized in that: At least the following steps are included: (1) placing the fluorinated polymer matrix into an internal mixer for premixing to obtain a fluorinated polymer premix; (2) adding an internal mold release agent, a wear-resistant material and a lubricating dispersant to the fluorine-containing polymer premix in parts by weight, and mixing to obtain a mixture A; (3) Adding a plasticizer, a filler and carbon black to mixture A according to parts by weight, and kneading to obtain mixture B; (4) After the mixture B is cooled, a vulcanizing agent, a co-crosslinking agent and an accelerator are added, and the mixture is vulcanized to obtain the product.

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