Metal rubber composite material applied to liquid hydrogen sealing and preparation process

Abstract

The invention discloses a metal rubber composite material applied to liquid hydrogen sealing and a preparation process, and belongs to the field of high-molecular compound compositions.The composite material comprises, by weight, a rubber matrix and necessary components; the rubber matrix comprises 50-70 parts of polytetrafluoroethylene, 10-20 parts of polyimide, 5-15 parts of graphite, 4-6 parts of carbon fibers, 2-4 parts of molybdenum disulfide, 2-6 parts of glass fibers, 1-3 parts of a liquid crystal polymer, 0.5-1.5 parts of metal micro powder, 3-7 parts of silicone rubber and 1-3 parts of fluororubber; the necessary components comprise 3-7.5 parts of an accelerant, 1-3 parts of a coupling agent and 2-5 parts of an anti-aging agent; the accelerant comprises a main accelerant, an auxiliary accelerant and a vulcanization activator, and the main accelerant is at least one or more of thiazoles; the invention aims to solve the problems that in the prior art, when a composite material is mixed, due to the lack of an accelerant, the molded sealing ring consumes too long time during vulcanization, and the crosslinking density during vulcanization is insufficient.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid hydrogen pump sealing, and in particular to a metal-rubber composite material used for liquid hydrogen sealing and a preparation process thereof. Background Art

[0002] Liquid hydrogen pump sealing technology is one of the key technologies in the aerospace and energy fields, and is mainly used in liquid hydrogen storage and transportation systems. As an efficient and clean fuel, liquid hydrogen is widely used in fields such as rocket propulsion and hydrogen-powered vehicles. However, the characteristics of liquid hydrogen at extremely low temperatures make it face many challenges in the sealing process, such as shrinkage and embrittlement of the material due to temperature changes, which may lead to seal failure. Therefore, the development of high-performance sealing materials and structures to ensure the safety and stability of liquid hydrogen during storage and transportation has become a research focus. This technology is not only related to the effective use of liquid hydrogen, but also has important significance for improving the safety and reliability of the overall system.

[0003] The invention patent with application number: CN202011228163.7 and publication number: CN112521667A (hereinafter referred to as "prior art 1") discloses a composite rubber, a high wear-resistant sealing composite material and a preparation method thereof. The high wear-resistant sealing composite material of the present invention comprises the following components in parts by weight: composite rubber: 133-150 parts, carbon black: 50-70 parts, vulcanizing agent: 4-8 parts, coupling agent: 4-7 parts, plasticizer: 2-8 parts, antioxidant: 3.5-7 parts, active zinc oxide: 3-5 parts, stearic acid: 0.5-1.5 parts; the composite rubber comprises the following components in parts by weight: nitrile rubber: 80-90 parts, polyurethane rubber: 20-10 parts, polytetrafluoroethylene powder: 20-30 parts, nano-reinforcement agent: 12-18 parts, and organic tin heat stabilizer: 1-2 parts.

[0004] The specification of prior art 1 discloses a composite rubber, a highly wear-resistant seal composite material and a preparation method thereof. When in use, the composite rubber is first refined separately, and then other materials are added step by step for mixing. The composite material is obtained through reasonable formula design and process optimization. However, in actual applications, since the sealing ring needs to be vulcanized after molding to improve the performance of the sealing ring, without the addition of an accelerator, the reaction speed of pure vulcanizing agent (such as sulfur) with rubber molecules is very slow. Vulcanization by high-temperature heating alone may take several hours or even longer to complete the vulcanization process. In addition, without the addition of an accelerator, the vulcanization reaction efficiency of the rubber base material itself is low. When there is no accelerator, less chemical bonds are formed between sulfur and rubber molecules, and the cross-linking density is insufficient. Summary of the invention

[0005] The present invention provides a metal-rubber composite material for liquid hydrogen sealing and a preparation process thereof, aiming to solve the problem in the prior art that, when the composite material is mixed, a accelerator is lacking, which results in a long time spent on vulcanization of the formed sealing ring and insufficient cross-linking density during vulcanization.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A metal-rubber composite material used for liquid hydrogen sealing, the components of which, by weight, include: a rubber matrix and necessary components;

[0008] The rubber matrix comprises: 50-70 parts of polytetrafluoroethylene, 10-20 parts of polyimide, 5-15 parts of graphite, 4-6 parts of carbon fiber, 2-4 parts of molybdenum disulfide, 2-6 parts of glass fiber, 1-3 parts of liquid crystal polymer, 0.5-1.5 parts of metal powder, 3-7 parts of silicone rubber and 1-3 parts of fluororubber;

[0009] The necessary components include: 3-7.5 parts of accelerator, 1-3 parts of coupling agent and 2-5 parts of antioxidant; the accelerator includes a main accelerator, an auxiliary accelerator and a vulcanization activator, the main accelerator is at least one or more of thiazoles, and the thiazoles account for 0.5-1.5 parts of the rubber base material.

[0010] Furthermore, the rubber matrix contains: 55-65 parts of polytetrafluoroethylene, 12-18 parts of polyimide, 8-12 parts of graphite, 4.5-5.5 parts of carbon fiber, 1.5-3.5 parts of molybdenum disulfide, 3-5 parts of glass fiber, 1.5-2.5 parts of liquid crystal polymer, 0.75-1.25 parts of metal powder, 4-6 parts of silicone rubber and 1.5-2.5 parts of fluororubber.

[0011] Further, the primary accelerator includes at least one of 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxydiethylbenzothiazole sulfenamide, diisopropylthioaminobenzothiazole, 2-mercaptobenzothiazole zinc salt and N-methyldibenzothiazole sulfenamide.

[0012] Furthermore, the auxiliary accelerator is at least one of guanidines, and the vulcanization activator is at least one of zinc oxide and stearic acid.

[0013] Furthermore, the guanidine auxiliary accelerator includes at least one of diphenylguanidine, N,N'-diphenylthiourea, N,N'-dicyclohexylthiourea and tolueneguanidine.

[0014] Furthermore, the coupling agent includes at least one of a silane coupling agent and a titanate coupling agent.

[0015] Furthermore, the antioxidant includes phenolic antioxidant, amine antioxidant and anti-ozonating antioxidant, and the components thereof are calculated by weight as follows: 0.5-2 parts of phenolic antioxidant, 1-2 parts of amine antioxidant and 0.5-1 part of anti-ozonating antioxidant.

[0016] Furthermore, the essential components also include 0.5-1 parts of a low-temperature flexibility modifier, 3-6 parts of a filler, and 1-2 parts of a toughening agent.

[0017] A preparation process of a metal-rubber composite material used for liquid hydrogen sealing, comprising using the composite material to prepare a sealing ring, the preparation process comprising the following steps:

[0018] (1) adjusting the temperature and speed of the mixer, adding the rubber base material and necessary components into the mixer in sequence for mixing, and finally collecting the refined rubber material;

[0019] (2) placing the refined rubber material into an injection mold for molding, and finally completing the molding of the sealing ring, and taking out the sealing ring after molding;

[0020] (3) Trim the formed sealing ring to ensure that there are no burrs on the surface of the sealing ring;

[0021] (4) Put the shaped sealing ring into a vulcanizing furnace for vulcanization;

[0022] (5) Take out the vulcanized sealing ring;

[0023] (6) Measure the thickness of the sealing ring. If the thickness is qualified, collect it. If the thickness is greater than 5 mm, repeat step (4) and perform vulcanization again for 1-2 minutes.

[0024] Furthermore, in step (4), the temperature in the vulcanization furnace is 160° C.-180° C., the vulcanization pressure in the vulcanization furnace is 8 MPa-12 MPa, and the vulcanization time is 8-15 min.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The invention mainly comprises a rubber matrix and necessary components. In actual use, a staff first adjusts the temperature and rotation speed of a mixer, sequentially adds the rubber base material and necessary components into the mixer for mixing, then collects the refined rubber material, then puts the refined rubber material into an injection mold for molding, finally completes the molding of the sealing ring, and takes out the sealing ring after molding; then the molded sealing ring is trimmed to ensure that there are no burrs on the surface of the sealing ring, then the shaped sealing ring is put into a vulcanizing furnace for vulcanization, and finally the vulcanized sealing ring is taken out to form a finished sealing ring. In this process, the thickness of the sealing ring needs to be measured, and the thickness of the sealing ring is measured. If the thickness is qualified, it is collected, and if the thickness is greater than 5mm, it is vulcanized again for 1-2 minutes. The advantage of such a setting is that the addition of a thiazole accelerator, a coupling agent and an antioxidant into the rubber base material can enable the sealing ring to cause sulfur and rubber molecules to undergo a rapid and sufficient cross-linking reaction during the vulcanization process, thereby making the overall vulcanization process of the sealing ring more efficient and more effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is one of the structural schematic diagrams of the preparation device in the present invention.

[0029] Figure 2 This is the second structural schematic diagram of the preparation device in the present invention.

[0030] In the figure, 101-frame, 102-upper adjusting plate, 103-lower adjusting plate, 104-telescopic assembly, 105-first heating roller, 106-second heating roller, 107-support rod, 108-hinge part, 109-connecting bar, 110-motor, 111-sprocket transmission mechanism, 112-gear transmission mechanism. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with embodiments, which are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0032] This embodiment discloses a metal-rubber composite material for liquid hydrogen sealing, and its components, measured by weight, include: a rubber matrix and necessary components;

[0033] The rubber matrix comprises: 50-70 parts of polytetrafluoroethylene, 10-20 parts of polyimide, 5-15 parts of graphite, 4-6 parts of carbon fiber, 2-4 parts of molybdenum disulfide, 2-6 parts of glass fiber, 1-3 parts of liquid crystal polymer, 0.5-1.5 parts of metal powder, 3-7 parts of silicone rubber and 1-3 parts of fluororubber;

[0034] The necessary components include: 3-7.5 parts of accelerator, 1-3 parts of coupling agent and 2-5 parts of antioxidant; the accelerator includes a main accelerator, an auxiliary accelerator and a vulcanization activator, the main accelerator is at least one or more of thiazoles, and the thiazoles are 0.5-1.5 parts of the rubber base material;

[0035] The invention mainly comprises a rubber matrix and necessary components. In actual use, a staff first adjusts the temperature and rotation speed of a mixer, sequentially adds the rubber base material and necessary components into the mixer for mixing, then collects the refined rubber material, then puts the refined rubber material into an injection mold for molding, finally completes the molding of the sealing ring, and takes out the sealing ring after molding; then the molded sealing ring is trimmed to ensure that there are no burrs on the surface of the sealing ring, then the shaped sealing ring is put into a vulcanizing furnace for vulcanization, and finally the vulcanized sealing ring is taken out to form a finished sealing ring. In this process, the thickness of the sealing ring needs to be measured, and the thickness of the sealing ring is measured. If the thickness is qualified, it is collected, and if the thickness is greater than 5mm, it is vulcanized again for 1-2 minutes. The advantage of such a setting is that the addition of a thiazole accelerator, a coupling agent and an antioxidant into the rubber base material can enable the sealing ring to cause sulfur and rubber molecules to undergo a rapid and sufficient cross-linking reaction during the vulcanization process, thereby making the overall vulcanization process of the sealing ring more efficient and more effective.

[0036] In some embodiments, the rubber matrix comprises: 55-65 parts of polytetrafluoroethylene, 12-18 parts of polyimide, 8-12 parts of graphite, 4.5-5.5 parts of carbon fiber, 1.5-3.5 parts of molybdenum disulfide, 3-5 parts of glass fiber, 1.5-2.5 parts of liquid crystal polymer, 0.75-1.25 parts of metal powder, 4-6 parts of silicone rubber and 1.5-2.5 parts of fluororubber.

[0037] As an optional implementation, in this embodiment, the rubber base material is selected by weight as 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber and 2 parts of fluororubber; the necessary components are selected by weight as 1 part of main catalyst, 0.75 parts of auxiliary catalyst, 3.5 parts of vulcanization activator, 2 parts of coupling agent and 3.5 parts of antioxidant.

[0038] When in use, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal micropowder, 5 parts of silicone rubber and 2 parts of fluororubber are first poured into a mixer for mixing, and then 1 part of the main catalyst, 0.75 parts of the auxiliary catalyst, 3.5 parts of the vulcanization activator, 2 parts of the coupling agent and 3.5 parts of the antioxidant are added and mixed so that the accelerator, coupling agent and antioxidant are added to the rubber base material.

[0039] In some embodiments, the primary accelerator includes at least one of 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxydiethylbenzothiazole sulfenamide, diisopropylthioaminobenzothiazole, 2-mercaptobenzothiazole zinc salt and N-methyldibenzothiazole sulfenamide.

[0040] In some embodiments, the auxiliary accelerator is at least one of guanidines, and the vulcanization activator is at least one of zinc oxide and stearic acid.

[0041] In some embodiments, the guanidine auxiliary accelerator includes at least one of diphenylguanidine, N,N'-diphenylthiourea, N,N'-dicyclohexylthiourea and tolueneguanidine.

[0042] In some embodiments, the coupling agent includes at least one of a silane coupling agent and a titanate coupling agent.

[0043] In some embodiments, the antioxidant includes a phenolic antioxidant, an amine antioxidant and an ozone antioxidant, and the components thereof are calculated by weight: 0.5-2 parts of the phenolic antioxidant, 1-2 parts of the amine antioxidant, and 0.5-1 part of the ozone antioxidant.

[0044] In actual use, the components are calculated by weight: 1.25 parts of phenol antioxidant, 1.5 parts of amine antioxidant, and 0.75 parts of ozone antioxidant.

[0045] In some embodiments, the essential components further include 0.5-1 parts of a low temperature flexibility modifier, 3-6 parts of a filler, and 1-2 parts of a toughening agent.

[0046] In actual use, the components need to be added by weight: 0.75 parts of gentle and flexible modifier, 4.5 parts of filler, and 1.5 parts of toughening agent.

[0047] As an optional implementation, in this embodiment, the main accelerators are 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfonamide, N-tert-butyl-2-benzothiazole sulfonamide, N-oxydiethylbenzothiazole sulfonamide, diisopropylthioaminobenzothiazole, 2-mercaptobenzothiazole zinc salt and N-methyldibenzothiazole sulfonamide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, and the coupling agent is silane coupling agent. Then, an antioxidant, 0.75 parts of a gentle and flexible modifier, 4.5 parts of a filler and 1.5 parts of a toughening agent are added, and 8 different main accelerators are added respectively, while other materials remain unchanged. 8 experiments are carried out to test the hardness, tensile strength and elongation at break of the sealing ring. The purpose is to test which main accelerator has the best mixing effect on the sealing ring.

[0048] When 2-mercaptobenzothiazole is selected as the main accelerator, diphenylguanidine is selected as the guanidine auxiliary accelerator, zinc oxide is selected as the vulcanization activator, and silane coupling agent is selected as the coupling agent, then antioxidant, 0.75 parts of gentle and flexible modifier, 4.5 parts of filler and 1.5 parts of toughening agent are added, and recorded as Experiment 1;

[0049] The specific operation method in Experiment 1 is as follows:

[0050] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of 2-mercaptobenzothiazole, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0051]

[0052] In some embodiments, when the main accelerator is dibenzothiazole disulfide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is a silane coupling agent, and then an antioxidant, 0.75 parts of a gentle and flexible modifier, 4.5 parts of a filler, and 1.5 parts of a toughening agent are added, and recorded as Experiment 2;

[0053] The specific operation methods in Experiment 2 are as follows:

[0054] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of dibenzothiazole disulfide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0055]

[0056] In some embodiments, when the main accelerator is N-cyclohexyl-2-benzothiazole sulfenamide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is a silane coupling agent, and then an antioxidant, 0.75 parts of a gentle and flexible modifier, 4.5 parts of a filler, and 1.5 parts of a toughening agent are added, and the result is recorded as Experiment 3;

[0057] The specific operation methods in Experiment 3 are as follows:

[0058] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of N-cyclohexyl-2-benzothiazole sulfonamide, 0.75 parts of diphenyl guanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0059]

[0060] In some embodiments, when the main accelerator is N-tert-butyl-2-benzothiazole sulfenamide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is a silane coupling agent, and then an antioxidant, 0.75 parts of a gentle and flexible modifier, 4.5 parts of a filler, and 1.5 parts of a toughening agent are added, and recorded as Experiment 4;

[0061] The specific operation methods in Experiment 4 are as follows:

[0062] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of N-tert-butyl-2-benzothiazole sulfonamide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0063]

[0064]

[0065] In some embodiments, when the main accelerator is N-oxydiethylbenzothiazolesulfonamide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is a silane coupling agent, and then an antioxidant, 0.75 parts of a soft and flexible modifier, 4.5 parts of a filler, and 1.5 parts of a toughening agent are added, and the result is recorded as Experiment 5;

[0066] The specific operation methods in Experiment 5 are as follows:

[0067] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of N-oxydiethylbenzothiazolesulfonamide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0068]

[0069] In some embodiments, when the main accelerator is diisopropylthioaminobenzothiazole, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is a silane coupling agent, and then an antioxidant, 0.75 parts of a soft and flexible modifier, 4.5 parts of a filler, and 1.5 parts of a toughening agent are added, and the result is recorded as Experiment 6;

[0070] The specific operation methods in Experiment 6 are as follows:

[0071] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of diisopropylthioaminobenzothiazole, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0072]

[0073] In some embodiments, when the main accelerator is 2-mercaptobenzothiazole zinc salt, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is silane coupling agent, and then an antioxidant, 0.75 parts of a soft and flexible modifier, 4.5 parts of a filler, and 1.5 parts of a toughening agent are added, and recorded as Experiment 7;

[0074] The specific operation methods in Experiment 7 are as follows:

[0075] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of 2-mercaptobenzothiazole zinc salt, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0076]

[0077] In some embodiments, when the main accelerator is N-methyldibenzothiazolesulfonamide, the guanidine auxiliary accelerator is diphenylguanidine, the vulcanization activator is zinc oxide, the coupling agent is a silane coupling agent, and then an antioxidant, 0.75 parts of a soft and flexible modifier, 4.5 parts of a filler, and 1.5 parts of a toughening agent are added, and recorded as Experiment 8;

[0078] The specific operation methods in Experiment 8 are as follows:

[0079] First, 60 parts of polytetrafluoroethylene, 15 parts of polyimide, 10 parts of graphite, 55 parts of carbon fiber, 3 parts of molybdenum disulfide, 4 parts of glass fiber, 2 parts of liquid crystal polymer, 1 part of metal powder, 5 parts of silicone rubber and 2 parts of fluororubber were poured into a mixer for mixing, and then 1 part of N-methyldibenzothiazolesulfonamide, 0.75 parts of diphenylguanidine, 3.5 parts of zinc oxide, 2 parts of silane coupling agent, 3.5 parts of antioxidant, 0.75 parts of gentle flexibility modifier, 4.5 parts of filler and 1.5 parts of toughening agent were poured into the mixer and mixed with the above rubber base material. The mixed rubber material was tested for the hardness of the sealing ring by a hardness tester, and the tensile strength and elongation at break were tested by a tensile test tool; the experimental data are as follows:

[0080]

[0081] Therefore, the appropriate primary accelerator can be selected based on the data in Experiments 1 to 8 according to the actual requirements of hardness, tensile strength and elongation at break.

[0082] In some different embodiments, the present invention also includes a preparation process of a metal-rubber composite sealing ring for liquid hydrogen sealing, comprising preparing the sealing ring using the above composite material, and the preparation process includes the following steps:

[0083] (1) adjusting the temperature and speed of the mixer, adding the rubber base material and necessary components into the mixer in sequence for mixing, and finally collecting the refined rubber material;

[0084] (2) placing the refined rubber material into an injection mold for molding, and finally completing the molding of the sealing ring, and taking out the sealing ring after molding;

[0085] (3) Trim the formed sealing ring to ensure that there are no burrs on the surface of the sealing ring;

[0086] (4) Put the shaped sealing ring into a vulcanizing furnace for vulcanization;

[0087] (5) Take out the vulcanized sealing ring;

[0088] (6) Measure the thickness of the sealing ring. If the thickness is qualified, collect it. If the thickness is greater than 5 mm, repeat step (4) and perform vulcanization again for 1-2 minutes.

[0089] Furthermore, in step (4), the temperature in the vulcanization furnace is 160° C.-180° C., the vulcanization pressure in the vulcanization furnace is 8 MPa-12 MPa, and the vulcanization time is 8-15 min.

[0090] See also Figure 1 as well as Figure 2As shown, in some different embodiments, the sealing ring is prepared by a preparation device, wherein the preparation device includes a mixing device, a compression molding device and a vulcanization device; the mixing device is used to mix the raw materials and additives to form a rubber material; the compression molding device is used to compression mold the rubber material; and the vulcanization device is used to vulcanize the formed sealing ring to enhance the mechanical strength, heat resistance and elasticity of the sealing ring;

[0091] Among them, the mixing device includes a frame 101, a driving component, a heating roller group and an adjusting component. The driving component is installed on the frame 101, and the heating roller group is rotatably installed on the frame 101. The driving component is used to drive the heating roller group to rotate. The adjusting component includes an upper adjusting plate 102 and a lower adjusting plate 103. The upper adjusting plate 102 is located directly above the heating roller group. The heating roller group and the upper adjusting plate 102 are slidably matched. The upper adjusting plate 102 is used to adjust the width of the raw materials to be mixed. The lower adjusting plate 103 is rotatably installed below the heating roller group through a telescopic component 104. The telescopic component 104 is hinged on the frame 101. The lower adjusting plate 103 is used to adjust the thickness of the raw materials to be mixed.

[0092] The present invention mainly comprises a mixing device, a film forming device and a vulcanizing device; in actual use, the staff first puts the raw materials for making the sealing ring into a container, then slides the position of the upper adjusting plate 102 above the hot roller group to form a certain width between the two upper adjusting plates 102, then controls the telescopic component 104 to extend, and after the telescopic component 104 extends, controls the lower adjusting plate 103 to rotate, thereby making a gap between the lower adjusting plate 103 and the hot roller group; then pours the raw materials for the sealing ring in the container just above the heated roller group, then starts the driving component, and the driving component controls the hot roller group to rotate in opposite directions, thereby repeatedly rolling the raw materials for making the sealing ring, when the raw materials for making the sealing ring are squeezed and mixed by the hot roller group, they stick to the hot roller group and rotate with the hot roller group, at this time, the glue sticking to the hot roller group is first adjusted by the lower adjusting plate 103 to form a certain thickness, which is slightly smaller than the gap between the lower adjusting plate 103 and the hot roller group, and the glue is rolled from the hot roller group. When the lower part of the roller group turns to the upper part of the hot roller group, the position of the rubber stuck on the hot roller group is restricted by the upper regulating plate 102. At this time, the rubber stuck on the hot roller group moves between the two upper regulating plates 102. The two upper regulating plates 102 gather the rubber stuck on the hot roller group, and then repeatedly refine the rubber stuck on the hot roller group to form a mixed rubber material. The refined rubber is then placed in a compression molding device for molding to form a sealing ring. Finally, the molded sealing ring is placed in a vulcanizing device for vulcanization, so that the mechanical strength, heat resistance and elasticity of the sealing ring are better. The advantage of this arrangement is that the position of the rubber stuck on the hot roller group is adjusted by the upper regulating plate 102 and the lower regulating plate 103, and there is no need to manually adjust the position of the rubber stuck on the hot roller group, which can save labor costs. In addition, through the arrangement of the upper regulating plate 102 and the lower regulating plate 103, the rubber stuck on the hot roller group can also be better gathered, thereby achieving a better rubber refining effect.

[0093] In some embodiments, the heating roller group includes a first heating roller 105 and a second heating roller 106, and the first heating roller 105 and the second heating roller 106 are both rotatably mounted on the frame 101, and the bottom edge of the upper adjustment plate 102 is used to contact the first heating roller 105 and the second heating roller 106, and the lower adjustment plate 103 is used to contact the rubber material on the first heating roller 105 and the second heating roller 106.

[0094] During actual use, the staff pours the raw material for making the sealing ring on top of the first heating roller 105 and the second heating roller 106. The first heating roller 105 and the second heating roller 106 rotate in opposite directions to crush the raw material for making the sealing ring, so that the raw material for making the sealing ring sticks to the first heating roller 105 and the second heating roller 106. Through the continuous rotation of the first heating roller 105 and the second heating roller 106, the glue on the second heating roller 106 adheres to the first heating roller 105, finally forming a rubber material.

[0095] In some embodiments, two support rods 107 and two hinged parts 108 are provided on the frame 101. The support rods 107 are rotatably connected to the frame 101. A connecting strip 109 is fixedly installed on the support rods 107. One end of the telescopic assembly 104 is hinged to the connecting strip 109 and the other end is hinged to the hinged part 108. Each support rod 107 is fixedly installed with a lower adjustment plate 103.

[0096] In actual use, there are two telescopic assemblies 104, which are respectively hinged on the frame 101 and located at the bottom of the first heating roller 105 and the second heating roller 106;

[0097] As an optional implementation, in this embodiment, the telescopic component 104 is specifically a cylinder. When in use, when the cylinder is extended, the movable end of the cylinder pushes the connecting bar 109, and the connecting bar 109 pulls the support rod 107 to make the support rod 107 rotate around the frame 101. Since the support rod 107 is fixedly connected to the lower adjustment plate 103, the support rod 107 rotates and then makes the lower adjustment plate 103 rotate in the direction close to the hot roller group, thereby realizing the adjustment of the angle of the lower adjustment plate 103.

[0098] In some embodiments, the driving assembly includes a motor 110 and a transmission mechanism. The motor 110 is mounted on the frame 101 . The motor 110 drives the first heating roller 105 and the second heating roller 106 to rotate on the frame 101 through the transmission mechanism.

[0099] In actual use, the transmission mechanism mainly includes a sprocket transmission mechanism 111 and a gear transmission mechanism 112, wherein the motor 110 drives the first heating roller 105 to rotate through the sprocket rotation mechanism, and drives the second heating roller 106 to rotate through the gear transmission mechanism 112;

[0100] As an optional implementation, in this embodiment, the sprocket transmission mechanism 111 includes a driving sprocket, a driven sprocket and a chain, and the gear transmission mechanism 112 includes a driving gear and a driven gear, wherein the driving sprocket is fixedly mounted on the output shaft of the motor 110, the driven sprocket is fixedly mounted on the end of the first heating roller 105, the driving gear is fixedly mounted on the end of the first heating roller 105 away from the driven sprocket, and the driven gear is fixedly mounted on the end of the second heating roller 106 close to the driving gear, the driving gear and the driven gear are meshed with each other, and the chain is sleeved on the driving sprocket and the driven sprocket.

[0101] When in use, the motor 110 drives the driving sprocket to rotate, and after the driving sprocket rotates, it drives the driven sprocket to rotate under the action of the chain, and after the driven sprocket rotates, the first heating roller 105 rotates, and after the first heating roller 105 rotates, under the action of the mutual meshing of the driving gear and the driven gear, the second heating roller 106 rotates along with the first heating roller 105. Since the driving gear and the driven gear form an external meshing, the rotation directions of the first heating roller 105 and the second heating roller 106 are opposite, and the first heating roller 105 and the second heating roller 106 rotate in opposite directions to each other.

[0102] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "two ends", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0103] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include at least one of such features.

[0104] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0105] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A metal-rubber composite material for liquid hydrogen sealing, characterized in that: The components of the composite material are measured by weight and include: a rubber matrix and necessary components; The rubber matrix comprises: 50-70 parts of polytetrafluoroethylene, 10-20 parts of polyimide, 5-15 parts of graphite, 4-6 parts of carbon fiber, 2-4 parts of molybdenum disulfide, 2-6 parts of glass fiber, 1-3 parts of liquid crystal polymer, 0.5-1.5 parts of metal powder, 3-7 parts of silicone rubber and 1-3 parts of fluororubber; The necessary components include: 3-7.5 parts of accelerator, 1-3 parts of coupling agent and 2-5 parts of antioxidant; the accelerator includes a main accelerator, an auxiliary accelerator and a vulcanization activator, the main accelerator is at least one or more of thiazoles, and the thiazoles account for 0.5-1.5 parts of the rubber base material.

2. The metal-rubber composite material for liquid hydrogen sealing according to claim 1, characterized in that: The rubber matrix comprises: 55-65 parts of polytetrafluoroethylene, 12-18 parts of polyimide, 8-12 parts of graphite, 4.5-5.5 parts of carbon fiber, 1.5-3.5 parts of molybdenum disulfide, 3-5 parts of glass fiber, 1.5-2.5 parts of liquid crystal polymer, 0.75-1.25 parts of metal powder, 4-6 parts of silicone rubber and 1.5-2.5 parts of fluororubber.

3. The metal-rubber composite material for liquid hydrogen sealing according to claim 1, characterized in that: The primary accelerator includes at least one of 2-mercaptobenzothiazole, dibenzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, N-oxydiethylbenzothiazole sulfenamide, diisopropylthioaminobenzothiazole, 2-mercaptobenzothiazole zinc salt and N-methyldibenzothiazole sulfenamide.

4. The metal-rubber composite material for liquid hydrogen sealing according to claim 1, characterized in that: The auxiliary accelerator is at least one of guanidines, and the vulcanization activator is at least one of zinc oxide and stearic acid.

5. The metal-rubber composite material for liquid hydrogen sealing according to claim 4, characterized in that: The guanidine auxiliary accelerator includes at least one of diphenylguanidine, N,N'-diphenylthiourea, N,N'-dicyclohexylthiourea and tolueneguanidine.

6. The metal-rubber composite material for liquid hydrogen sealing according to claim 1, characterized in that: The coupling agent includes at least one of a silane coupling agent and a titanate coupling agent.

7. The metal-rubber composite material for liquid hydrogen sealing according to claim 2, characterized in that: The antioxidant comprises phenol antioxidant, amine antioxidant and ozone antioxidant, and the components thereof are calculated by weight, comprising 0.5-2 parts of phenol antioxidant, 1-2 parts of amine antioxidant and 0.5-1 part of ozone antioxidant.

8. The metal-rubber composite material for liquid hydrogen sealing according to claim 1, characterized in that: The necessary components also include 0.5-1 parts of low temperature flexibility modifier, 3-6 parts of filler, and 1-2 parts of toughening agent.

9. A process for preparing a metal-rubber composite material for liquid hydrogen sealing, comprising using the metal-rubber composite material for liquid hydrogen sealing according to any one of claims 1 to 8 to prepare a sealing ring, characterized in that: The preparation process includes the following steps: (1) adjusting the temperature and speed of the mixer, adding the rubber base material and necessary components into the mixer in sequence for mixing, and finally collecting the refined rubber material; (2) placing the refined rubber material into an injection mold for molding, and finally completing the molding of the sealing ring, and taking out the sealing ring after molding; (3) Trim the formed sealing ring to ensure that there are no burrs on the surface of the sealing ring; (4) Put the shaped sealing ring into a vulcanizing furnace for vulcanization; (5) Take out the vulcanized sealing ring; (6) Measure the thickness of the sealing ring. If the thickness is qualified, collect it. If the thickness is greater than 5 mm, repeat step (4) and perform vulcanization again for 1-2 minutes.

10. The process for preparing a metal-rubber composite material for liquid hydrogen sealing according to claim 9, characterized in that: In step (4), the temperature in the vulcanization furnace is 160° C.-180° C., the vulcanization pressure in the vulcanization furnace is 8 MPa-12 MPa, and the vulcanization time is 8-15 min.

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