A rubber gasket for a marine vessel and a method of making the same

Abstract

This invention discloses a marine rubber sealing gasket and its preparation method, belonging to the field of rubber sealing material processing technology. In the preparation of the marine rubber sealing gasket of this invention, a release film is first attached to the upper and lower surfaces of an uncured rubber sheet, and then vulcanized and the release film is peeled off. The raw material components of the uncured rubber sheet include: ethylene propylene diene monomer (EPDM) rubber, chlorinated butyl rubber, modified ethylene-α-octene copolymer, peroxide vulcanizing agent; crosslinking agent; reinforcing filler; plasticizer; activator; wherein the reinforcing filler includes... Flame-retardant organosilicon modified mica powder; the flame-retardant organosilicon is obtained by the hydrophosphorus addition reaction of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide with unsaturated siloxane and 2-hydroxy-4-vinylbenzaldehyde; the modified ethylene-α-octene copolymer is obtained by reacting with an aminated antioxidant; the aminated antioxidant is obtained by the demethylation of 3-methoxy-4-hydroxyacetophenone with 1,2-dibromoethane and then with 3-amino-1,2,4-triazol-5-thiol.

Description

Technical Field

[0001] This invention relates to the field of rubber sealing material processing technology, specifically to a marine rubber sealing gasket and its preparation method. Background Technology

[0002] As a vital pillar of the modern maritime economy, the shipbuilding industry prioritizes safety and reliability in its design and manufacturing processes. Within the complex structures of ship compartments, cable penetration devices are crucial for ensuring uninterrupted power and signal transmission, and the rubber gaskets within them play vital roles in waterproofing, fireproofing, shock absorption, and airtight isolation. With the continuous development of shipping technology, the performance requirements for marine rubber products have expanded beyond basic sealing functions, moving towards higher mechanical strength, superior aging resistance, and stringent flame-retardant standards. Especially in practical installation and maintenance scenarios, rubber gaskets in marine cable penetration devices are typically used in multi-layer stacking. This places more stringent and contradictory demands on the physical properties of the gasket surface: the gasket surface must possess moderate self-adhesion to temporarily bond and fix multiple gaskets during installation, preventing slippage and misalignment, while simultaneously ensuring that this adhesion is controllable for easy disassembly and reuse to meet the frequent needs of ship maintenance.

[0003] However, existing rubber gaskets still face significant technical bottlenecks in manufacturing processes and surface quality control, making it difficult to perfectly balance the aforementioned performance requirements. During the vulcanization process of rubber products, to prevent unvulcanized rubber from sticking to the high-temperature mold or hot plate, a separating material must be laid on the mold surface or the rubber surface. This process directly determines the surface microstructure of the finished gasket, thus affecting its final mechanical properties and user experience.

[0004] In the existing technology, commonly used isolation materials mainly include fabric, ordinary PET film and ordinary release paper or release film, but they all show obvious defects in practical applications.

[0005] Firstly, woven fabric is the most widely used insulating material in traditional processes, commonly including polyester, nylon, and cotton. The surface of the woven fabric has a specific texture formed by warp and weft weaving. Under the high temperature and pressure of vulcanization, these textures are clearly imprinted onto the rubber surface, creating a coarse or matte fine texture on the gasket. However, this surface texture negatively impacts the gasket's self-adhesion. For coarse-textured surfaces, the obvious unevenness significantly reduces the actual effective contact area when multiple layers of the gasket are stacked, weakening the van der Waals forces between molecules, thus significantly reducing self-adhesion. This makes slippage and misalignment highly likely when multiple layers are stacked, increasing the difficulty of installation. For fine-textured surfaces, although visually more delicate than coarse-textured surfaces, the uneven structure still exists at the microscopic level. Furthermore, during repeated use and peeling, fine fiber debris easily remains on the rubber surface. These residues not only contaminate the gasket surface but also form an insulating layer, severely affecting subsequent bonding. In addition, the fabric has a limited lifespan. After repeated use, the fibers wear off and fall off, causing the gasket surface to become abnormally smooth, making the self-adhesive properties extremely unstable and unable to guarantee the consistency of product quality.

[0006] Secondly, some manufacturers have tried using ordinary PET film as the insulating material. Although PET film has a smooth surface, it has strong adhesion to the rubber surface and is often difficult to peel off smoothly after vulcanization. Forcibly peeling it off can easily cause the film to tear, or even leave a layer of adhesive on the rubber surface, thus damaging the integrity of the gasket.

[0007] Finally, while some technologies use universal release paper or release film, these also present control challenges. If the release force is too high, it can lead to difficult peeling and damage to the rubber surface; if the release force is too low or a universal product is used, the rubber surface often becomes too smooth, resulting in insufficient self-adhesion and failing to meet the requirements for multi-layer stacking and fixing. More seriously, the release agent in ordinary release materials is prone to migration. Excessive migration can cause the rubber surface to completely lose its self-adhesion, even contaminating the mold and affecting subsequent batches of production.

[0008] In summary, developing a marine rubber gasket that can improve the mechanical, aging resistance, and flame retardant properties of the rubber composition itself, and that can obtain a surface without fabric texture and with stable and moderate self-adhesion through improved preparation process, is a technical problem that urgently needs to be solved in the field of marine equipment materials. Summary of the Invention

[0009] The purpose of this invention is to provide a rubber sealing gasket for ships and its preparation method, so as to solve the technical problems mentioned in the background art.

[0010] The technical solution to achieve the objective of this invention is: In a first aspect, the present invention provides a rubber sealing gasket for ships. The rubber sealing gasket for ships is prepared by first attaching a release film to the upper and lower surfaces of an uncured rubber sheet, and then vulcanizing and molding it to peel off the release film. The uncured rubber sheet, by mass parts, comprises the following raw material components: 100 parts EPDM rubber, 10-40 parts chlorinated butyl rubber, 11-14 parts modified ethylene-α-octene copolymer, 2-6 parts peroxide vulcanizing agent, 1-4 parts co-crosslinking agent, 20-60 parts reinforcing filler, 5-20 parts plasticizer, and 3-8 parts activator.

[0011] The release film is a PET release film coated with silicone oil on one side. The thickness of the PET release film is 50~125μm, preferably 75~100μm, the release force is 5~30 g / in, preferably 10~20g / in, and the surface roughness Ra≤ 0.1μm.

[0012] The self-adhesive peel force of the marine rubber gasket is 0.5~2.5 N / cm.

[0013] Furthermore, the reinforcing filler includes flame-retardant organosilicon-modified mica powder.

[0014] Furthermore, the flame-retardant organosilicon is obtained by a phosphorus hydroaddition reaction of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide with unsaturated siloxane and 2-hydroxy-4-vinylbenzaldehyde.

[0015] Furthermore, the modified ethylene-α-octene copolymer is obtained by reacting maleic anhydride-grafted POE with an amino-containing antioxidant.

[0016] Furthermore, the aminated antioxidant is obtained by reacting 3-methoxy-4-hydroxyacetophenone with 1,2-dibromoethane, followed by demethylation after reacting with 3-amino-1,2,4-triazol-5-thiol.

[0017] In a second aspect, the present invention provides a method for preparing a marine rubber gasket as described in the first aspect, the preparation steps including: (1) Weighing and preparing materials; (2) Mix flame-retardant organosilicon modified mica powder, modified ethylene-α-octene copolymer and 40-80 parts by weight of anhydrous ethanol, sonicate for 30-40 min, then add 10-15 parts by weight of 2-3M sodium hydroxide solution and stir for 6-8 h, with the addition time controlled within 30 min, then filter, wash and dry, and melt blend on a two-roll mill for 7-9 min, wherein the temperature of the two-roll mill is 110-130℃ and the rotation speed is 16 r / min to obtain mixture I; (3) Mix the mixture I with the remaining raw materials and then roll it into uncured rubber sheets on a two-roll mill; (4) Lay the PET release film flat on the lower hot plate of the flat vulcanizing machine, place the unvulcanized rubber sheet on the PET release film, cover the unvulcanized rubber sheet with the PET release film, then close the mold for vulcanization. After vulcanization, open the mold and peel off the PET release film on the unvulcanized rubber sheet to obtain the marine rubber sealing gasket.

[0018] The vulcanization temperature is 160~180℃, and the pressure is 10~20MPa; when the unvulcanized rubber sheet is 0.6mm, the vulcanization time is 2~4min; when the unvulcanized rubber sheet is 0.7mm, the vulcanization time is 2.5~5min; when the unvulcanized rubber sheet is 1mm, the vulcanization time is 3~6min. Further, the preparation steps of the modified ethylene-α-octene copolymer are as follows: 20-22 parts by mass of maleic anhydride-grafted POE and 1.8-2.2 parts by mass of aminated antioxidant are melt-blended on a two-roll mill to obtain the modified ethylene-α-octene copolymer; the temperature of the two-roll mill is 110-130℃ and the rotation speed is 16 r / min.

[0019] Furthermore, the preparation steps of the aminated antioxidant are as follows: A1. Take 1.6-1.7 parts by weight of 3-methoxy-4-hydroxyacetophenone, 2.7-2.8 parts by weight of anhydrous potassium carbonate, and 18-19 parts by weight of 1,2-dibromoethane and add them to 79-80 parts by weight of acetone. Stir and heat under reflux for 13-14 hours. After the reaction is complete, filter while hot and remove acetone and dibromoethane from the filtrate by vacuum distillation to obtain a solid residue. After washing and drying with distilled water, recrystallize with anhydrous ethanol to obtain bromoacetophenone. A2. Dissolve 1.1-1.2 parts by weight of 3-amino-1,2,4-triazol-5-thiol, 79-80 parts by weight of anhydrous ethanol, and 0.3-0.5 parts by weight of sodium hydroxide by magnetic stirring. Add 2.6-2.8 parts by weight of bromoacetophenone and reflux for 1-3 hours. Cool to room temperature and allow to stand. Filter, wash the solid with distilled water, dry, and place in 6.6-13.3 parts by weight of anhydrous dichloromethane. Cool to below 0°C under nitrogen protection. Add 2.5-2.7 parts by weight of trimethyliodosilane dropwise over 30 minutes. After the addition is complete, react at room temperature for 47-49 hours. Then add 1.3 parts by weight of methanol and continue stirring for 10-30 minutes. Next, remove methanol and dichloromethane by vacuum distillation. Filter, wash successively with sodium bisulfite aqueous solution, saturated sodium bicarbonate aqueous solution, and saturated brine, and dry to obtain the amino-modified antioxidant.

[0020] Further, the preparation method of the flame-retardant organosilicon modified mica powder is as follows: 1 part by mass of sericite powder, 144-180 parts by mass of anhydrous ethanol and 20 parts by mass of distilled water are mixed and stirred evenly. The pH value of the mixed solution is adjusted to 4.0 using acetic acid. Then, flame-retardant organosilicon is added and left to stand for 110-130 minutes to allow for complete hydrolysis. The amount of flame-retardant organosilicon is 5-7% of the mass of sericite powder. Finally, the mixture is kept at 98-102℃ for 110-130 minutes and then filtered. The mixture is washed with deionized water and centrifuged 2-4 times. Then, it is vacuum dried at 60℃ to obtain flame-retardant organosilicon modified mica powder.

[0021] Further, the preparation method of flame-retardant organosilicon is as follows: Under nitrogen protection, 3.8~4 parts by mass of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and 1.8~2 parts by mass of N,N-dimethylformamide are mixed, heated to 60~70℃, stirred for 30~60min, then 2.1~2.3 parts by mass of vinyltrimethoxysilane are added and stirred for 47~49h, then 2.1~2.3 parts by mass of 2-hydroxy-4-vinylbenzaldehyde are added, and the stirring reaction is continued for 47~49h. Then, the mixture is washed with dichloromethane and centrifuged to obtain flame-retardant organosilicon.

[0022] By adopting the above technical solution, the present invention has the following beneficial effects: 1. In the preparation of the marine rubber sealing gasket of the present invention, a release film is first attached to the upper and lower surfaces of the uncured rubber sheet, and then the release film is peeled off after vulcanization molding; the raw material components of the uncured rubber sheet include: EPDM rubber, chlorinated butyl rubber, modified ethylene-α-octene copolymer, peroxide vulcanizing agent, crosslinking agent, reinforcing filler, plasticizer, and activator. The resulting marine rubber sealing gasket has good flame retardancy, mechanical properties, and aging resistance, and the surface of the marine rubber sealing gasket has neither fabric texture nor stable and moderate self-adhesion.

[0023] 2. The release film of this invention uses a PET release film with silicone oil coated on one side. The thickness of the PET release film is 50~125μm. When the thickness is <50μm, the release film is prone to wrinkling and cracking under vulcanization pressure, causing the rubber to adhere directly to the hot plate. When the thickness is too thick (>125μm), the film material is too rigid and difficult to adhere tightly to the rubber surface, which may produce bubbles or local release defects. The preferred thickness is 75~100μm, which takes into account flexibility, strength, and ease of operation. The release force is 5~30g / in. If the release force is too low (<5g / in), the silicone oil coating is too lubricating, and a large amount of silicone oil migrates to the rubber surface during vulcanization, which will permanently reduce the rubber's elasticity. Surface energy causes the gasket to completely lose its self-adhesiveness; excessively high release force (>30g / in) makes it difficult for the release film to peel off from the vulcanized rubber surface, and forcibly tearing it off may cause the rubber surface to tear or leave release agent residue; the preferred release force is 10~20g / in, which allows for smooth peeling while only a trace amount of silicone oil is transferred to the rubber surface. This trace amount of silicone oil will not destroy the self-adhesiveness provided by CIIR, but will instead make the adhesion more uniform and stable, and the rubber surface will maintain a bright gloss after peeling; surface roughness Ra≤0.1μm; the vulcanized rubber surface is bright and mirror-smooth, without any texture, and the self-adhesiveness is stable; there is no fiber residue; the surface gloss is high and the appearance quality is excellent.

[0024] 3. The reinforcing filler of the present invention includes flame-retardant organosilicon-modified mica powder. The flame-retardant organosilicon utilizes the active phosphorus-hydrogen bonds in the molecule of 2,4,8,10-tetraoxa-3,9-diphosphazaspiro[5.5]undecane 3,9-dioxide to undergo phosphorus-hydrogen addition reactions with unsaturated siloxanes and vinyl groups on 2-hydroxy-4-vinylbenzaldehyde, thereby successfully grafting 2-hydroxybenzaldehyde functional groups and rigid spirocyclic phosphate structures onto the siloxane molecular chain. This imparts excellent interfacial compatibility to the modified mica powder. When preparing marine rubber gaskets, it can significantly improve the dispersion uniformity of inorganic fillers in the rubber matrix, effectively avoiding the defects of easy agglomeration of traditional fillers, and thus greatly improving the overall mechanical properties and structural stability of the rubber gaskets. At the same time, the 2-hydroxybenzaldehyde functional group... The phenolic hydroxyl groups on the energy group act as a highly efficient "free radical scavenger," which can promptly terminate the peroxide free radicals and alkoxy free radicals generated during the rubber oxidation process, thereby blocking the transmission of the oxidation chain reaction and giving marine rubber gaskets good aging resistance, maintaining the elasticity and sealing performance of the gaskets. In addition, the introduction of the rigid spirocyclic phosphate ester structure allows the phosphorus element in the spirocyclic structure to promote the dehydration and carbonization of the matrix when heated during combustion, forming an initial carbon layer. Meanwhile, the organosilicon segments migrate to the material surface at high temperatures, decompose to generate an inorganic layer rich in silica, forming a dense and stable phosphorus-silicon composite carbon layer. The presence of the composite carbon layer can not only effectively isolate oxygen and external heat from the transfer to the inner rubber layer, but also inhibit the escape of internal combustible volatiles, thus playing an excellent flame retardant role in the condensed phase.

[0025] 4. The EPDM rubber used in this invention possesses excellent aging resistance, chemical corrosion resistance, superior electrical insulation, low density and high filling capacity, and good low-temperature flexibility. However, EPDM also has inherent defects such as poor self-adhesion and mutual adhesion, and poor oil resistance and flame retardancy. To solve these problems, this invention introduces chlorinated butyl rubber (CIIR) to modify EPDM through blending. Chlorinated butyl rubber has polar chlorine atoms, exhibiting good oil resistance, heat resistance, and chemical resistance, while also possessing high adhesive strength and excellent initial tack. Blending CIIR with EPDM can significantly improve the solvent resistance and physical and mechanical properties of EPDM. Furthermore, it effectively overcomes the shortcomings of EPDM's poor initial tack and self-adhesion, especially in improving oil resistance and flame retardancy. Since EPDM is a non-polar main-chain saturated rubber, while chlorinated butyl rubber is a main-chain unsaturated rubber containing polar chlorine atoms, there are significant differences between the two in polarity and saturation, resulting in poor compatibility and co-vulcanization performance. To address this, this invention introduces a modified ethylene-α-octene copolymer as a compatibilizer, which effectively improves the interfacial compatibility between EPDM and chlorinated butyl rubber, promotes the uniform dispersion and interfacial bonding of the two phases, and further enhances the mechanical properties of the blend system, providing a reliable guarantee for the preparation of high-performance marine rubber gaskets.

[0026] 5. The modified ethylene-α-octene copolymer of the present invention is obtained by grafting maleic anhydride onto POE and reacting it with an amino-containing antioxidant; wherein, the amino-modified antioxidant is obtained by first subjecting the phenolic hydroxyl group on 3-methoxy-4-hydroxyacetophenone to a nucleophilic substitution reaction with one end bromine atom of 1,2-dibromoethane, and then reacting the other end bromine atom with the thiol group on 3-amino-1,2,4-triazole-5-thiol, and finally reducing the original methoxy group to a more active phenolic hydroxyl group through a demethylation reaction, thereby obtaining an amino-modified antioxidant containing a triazole ring and a 4-ethoxy-3-hydroxyacetophenone structure. The introduced 4-ethoxy group... The active hydrogen on the phenolic hydroxyl group in the -3-hydroxyacetophenone structure can combine with the peroxide free radicals generated during the thermo-oxidative aging process of rubber, thereby terminating the free radical chain reaction and further improving the aging resistance of the material. The grafted triazole ring contains abundant nitrogen atoms, which can form stable coordinate bonds with metal ions (such as zinc ions). These coordinate bonds, together with the hydrogen bonds that may exist in the system, constitute a "hydrogen bond-coordinate bond" double dynamic crosslinking network. When this network structure is subjected to stress, the sacrificial bonds, i.e., the dynamic bonds, will preferentially break to dissipate energy and prevent the main chain from breaking, thereby significantly improving the tensile strength and elongation at break of the material.

[0027] 6. In preparing unvulcanized rubber sheets, this invention first places flame-retardant organosilicon-modified mica powder and modified ethylene-α-octene copolymer in an ethanol solvent and mixes them under the catalytic condition of sodium hydroxide to obtain mixture I; subsequently, mixture I is compounded with the remaining rubber components and calendered on a two-roll mill to obtain unvulcanized rubber sheets; wherein, the benzaldehyde structure grafted on the surface of the flame-retardant organosilicon-modified mica powder and the acetophenone structure on the side chain of the modified ethylene-α-octene copolymer undergo a Claisen-Schmidt condensation reaction under alkaline catalysis, removing one molecule of water to form an α,β-unsaturated ketone structure, i.e., a chalcone structure. The phenolic hydroxyl group in the chalcone structure can provide active hydrogen, acting as a free radical scavenger to terminate the free radical chain reaction during rubber oxidation. Simultaneously, the conjugated system in the chalcone structure can absorb ultraviolet energy and convert it into heat, thus acting as an ultraviolet absorber and effectively preventing the rubber molecular chains from breaking or cross-linking due to photo-oxidative aging. Furthermore, the rigid aromatic ring of the chalcone structure forms a large π-conjugated system with the α,β-unsaturated double bonds. This system not only acts as a physical cross-linking point to restrict the slippage of the rubber molecular chains but also dissipates external impact energy through electron cloud rearrangement within the large conjugated system, thereby further improving the tensile strength and tear resistance of the material. Detailed Implementation

[0028] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0030] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0032] PET release film: thickness 75μm; release force 15g / in; surface roughness Ra: 0.05μm; film width: 20 mm wider than uncured film.

[0033] Maleic anhydride grafted onto POE, with a maleic anhydride grafting rate of 1%.

[0034] The average particle size of sericite powder is 10 μm. Example 1

[0035] A method for preparing a rubber sealing gasket for ships, comprising the following steps: (1) Weighing and preparing materials: 100 parts EPDM; 20 parts CIIR; 11 parts modified ethylene-α-octene copolymer; 30 parts silica; 20 parts carbon black N550; 20 parts flame retardant organosilicon modified mica powder; 15 parts paraffin oil; 5 parts zinc oxide; 2 parts stearic acid; 3.5 parts BIPB peroxide; 2 parts TAIC crosslinking agent; (2) The flame-retardant organosilicon modified mica powder, modified ethylene-α-octene copolymer and 40 parts by weight of anhydrous ethanol were mixed and sonicated for 30 min. Then, 10 parts by weight of 3M sodium hydroxide solution were added dropwise and stirred for 6 h. The addition time was controlled within 30 min. Then, the mixture was filtered, washed and dried. It was melt-blended on a two-roll mill for 9 min. The temperature of the two-roll mill was 110℃ and the rotation speed was 16 r / min to obtain mixture I. (3) Add mixture I and EPDM to a 90°C internal mixer and mix for 5 minutes. Then add zinc oxide, silica, carbon black, 1 part stearic acid and 10 parts paraffin oil in sequence and mix for 5 minutes to obtain compound A. Add CIIR to a 70°C internal mixer and mix for 5 minutes. Then add the remaining paraffin oil, zinc oxide and stearic acid and mix for 5 minutes to obtain compound B. Add compound A and compound B to a two-roll mill and mix for 5 minutes. Then add peroxide and crosslinking agent in sequence. After the powder is absorbed, alternate between triangular wrapping and rolling 8 times each to produce a sheet with a thickness of 1 mm. (4) Lay the PET release film coated with silicone oil on one side with the silicone oil side facing up on the lower hot plate of the flat vulcanizing machine. Place the unvulcanized rubber sheet on the PET release film, and then cover the unvulcanized rubber sheet with the PET release film coated with silicone oil on one side with the silicone oil side facing down. Then close the mold and vulcanize. After vulcanization, open the mold and peel off the PET release film on the unvulcanized rubber sheet to obtain the marine rubber sealing gasket. The vulcanization temperature is 170℃, the pressure is 15MPa, and the vulcanization time is 5min.

[0036] The preparation steps of the modified ethylene-α-octene copolymer are as follows: 20 parts by mass of maleic anhydride-grafted POE and 1.8 parts by mass of aminated antioxidant are melt-blended on a two-roll mill for 8 min to obtain the modified ethylene-α-octene copolymer; the temperature of the two-roll mill is 110℃ and the rotation speed is 16 r / min.

[0037] The preparation steps of the aminated antioxidant are as follows: A1. Take 1.6 parts by mass of 3-methoxy-4-hydroxyacetophenone, 2.7 parts by mass of anhydrous potassium carbonate and 18 parts by mass of 1,2-dibromoethane and add them to 79 parts by mass of acetone. Stir and heat under reflux for 13 hours. After the reaction is complete, filter while hot and remove acetone and dibromoethane from the filtrate by vacuum distillation to obtain a solid residue. After washing and drying with distilled water, recrystallize with anhydrous ethanol to obtain bromoacetophenone. A2. Dissolve 1.1 parts by mass of 3-amino-1,2,4-triazol-5-thiol, 79 parts by mass of anhydrous ethanol, and 0.3 parts by mass of sodium hydroxide by magnetic stirring. Add 2.6 parts by mass of bromoacetophenone and reflux for 1 hour. Cool to room temperature and allow to stand. Filter, wash the solid with distilled water, dry, and place in 6.6 parts by mass of anhydrous dichloromethane. Cool to below 0°C under nitrogen protection. Add 2.5 parts by mass of trimethyliodosilane dropwise over 30 minutes. After the addition is complete, react at room temperature for 47 hours. Then add 1.3 parts by mass of methanol and continue stirring for 10 minutes. Next, remove methanol and dichloromethane by vacuum distillation. Filter, wash successively with sodium bisulfite aqueous solution, saturated sodium bicarbonate aqueous solution, and saturated brine, and dry to obtain the amino-modified antioxidant.

[0038] The preparation method of the flame-retardant organosilicon modified mica powder is as follows: 1 part by mass of sericite powder, 144 parts by mass of anhydrous ethanol and 20 parts by mass of distilled water are mixed and stirred evenly. The pH value of the mixed solution is adjusted to 4.0 with acetic acid. Then, flame-retardant organosilicon is added and left to stand for 110 min to allow for complete hydrolysis. The amount of flame-retardant organosilicon is 5% of the mass of sericite powder. Finally, the mixture is kept at 98℃ for 130 min and then filtered. The mixture is washed with deionized water and centrifuged twice. Then, it is vacuum dried at 60℃ to obtain flame-retardant organosilicon modified mica powder.

[0039] The preparation method of flame-retardant organosilicon is as follows: Under nitrogen protection, 3.8 parts by mass of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and 1.8 parts by mass of N,N-dimethylformamide are mixed, heated to 60℃, stirred for 60 min, and then 2.1 parts by mass of vinyltrimethoxysilane are added and stirred for 47 h. Then 2.1 parts by mass of 2-hydroxy-4-vinylbenzaldehyde are added and stirred for another 47 h. Finally, the mixture is washed with dichloromethane and centrifuged to obtain flame-retardant organosilicon.

[0040] The surface of the marine rubber sealing gasket has no fabric texture, and no microscopic bumps are visible under 50x magnification. When three 1.0mm gaskets are stacked and a pressure of 0.01MPa is applied for 10 seconds, they can be easily peeled off manually, with no residue on each layer. The peeling force retention rate is 92% after 10 stacking and peeling cycles. Example 2

[0041] A method for preparing a rubber sealing gasket for ships, comprising the following steps: (1) Weighing and preparing materials: 100 parts EPDM; 20 parts CIIR; 12 parts modified ethylene-α-octene copolymer; 30 parts silica; 20 parts carbon black N550; 40 parts flame retardant organosilicon modified mica powder; 15 parts paraffin oil; 5 parts zinc oxide; 2 parts stearic acid; 3.5 parts BIPB peroxide; 2 parts TAIC crosslinking agent; (2) The flame-retardant organosilicon modified mica powder, modified ethylene-α-octene copolymer and 60 parts by weight of anhydrous ethanol were mixed and sonicated for 35 min. Then, 12.5 parts by weight of 2.5M sodium hydroxide solution were added dropwise and stirred for 7 h. The addition time was controlled within 30 min. Then, the mixture was filtered, washed and dried. It was melt-blended on a two-roll mill for 8 min. The temperature of the two-roll mill was 120℃ and the rotation speed was 16 r / min to obtain mixture I. (3) Add mixture I and EPDM to a 90°C internal mixer and mix for 5 minutes. Then add zinc oxide, silica, carbon black, 1 part stearic acid and 10 parts paraffin oil in sequence and mix for 5 minutes to obtain compound A. Add CIIR to a 70°C internal mixer and mix for 5 minutes. Then add the remaining paraffin oil, zinc oxide and stearic acid and mix for 5 minutes to obtain compound B. Add compound A and compound B to a two-roll mill and mix for 5 minutes. Then add peroxide and crosslinking agent in sequence. After the powder is absorbed, alternate between triangular wrapping and rolling 8 times each to produce a sheet with a thickness of 1 mm. (4) Lay the PET release film coated with silicone oil on one side with the silicone oil side facing up on the lower hot plate of the flat vulcanizing machine. Place the unvulcanized rubber sheet on the PET release film, and then cover the unvulcanized rubber sheet with the PET release film coated with silicone oil on one side with the silicone oil side facing down. Then close the mold and vulcanize. After vulcanization, open the mold and peel off the PET release film on the unvulcanized rubber sheet to obtain the marine rubber sealing gasket. The vulcanization temperature is 170℃, the pressure is 15MPa, and the vulcanization time is 5min.

[0042] The preparation steps of the modified ethylene-α-octene copolymer are as follows: 21 parts by mass of maleic anhydride-grafted POE and 2 parts by mass of aminated antioxidant are melt-blended on a two-roll mill for 8 min to obtain the modified ethylene-α-octene copolymer; the temperature of the two-roll mill is 120℃ and the rotation speed is 16 r / min.

[0043] The preparation steps of the aminated antioxidant are as follows: A1. Take 1.65 parts by weight of 3-methoxy-4-hydroxyacetophenone, 2.76 parts by weight of anhydrous potassium carbonate and 18.5 parts by weight of 1,2-dibromoethane and add them to 79 parts by weight of acetone. Stir and heat under reflux for 14 hours. After the reaction is complete, filter while hot and remove acetone and dibromoethane from the filtrate by vacuum distillation to obtain a solid residue. After washing and drying with distilled water, recrystallize with anhydrous ethanol to obtain bromoacetophenone. A2. Dissolve 1.15 parts by mass of 3-amino-1,2,4-triazol-5-thiol, 79 parts by mass of anhydrous ethanol, and 0.4 parts by mass of sodium hydroxide by magnetic stirring. Add 2.7 parts by mass of bromoacetophenone and reflux for 2 hours. Cool to room temperature and allow to stand. Filter, wash the solid with distilled water, dry, and place in 13.3 parts by mass of anhydrous dichloromethane. Cool to below 0°C under nitrogen protection. Add 2.6 parts by mass of trimethyliodosilane dropwise over 30 minutes. After the addition is complete, react at room temperature for 48 hours. Then add 1.3 parts by mass of methanol and continue stirring for 20 minutes. Next, remove methanol and dichloromethane by vacuum distillation. Filter, wash successively with sodium bisulfite aqueous solution, saturated sodium bicarbonate aqueous solution, and saturated brine, and dry to obtain the amino-modified antioxidant.

[0044] The preparation method of the flame-retardant organosilicon modified mica powder is as follows: 1 part by mass of sericite powder, 144 parts by mass of anhydrous ethanol and 20 parts by mass of distilled water are mixed and stirred evenly. The pH value of the mixed solution is adjusted to 4.0 with acetic acid. Then, flame-retardant organosilicon is added and left to stand for 120 min to allow for complete hydrolysis. The amount of flame-retardant organosilicon is 6% of the mass of sericite powder. Finally, the mixture is kept at 100℃ for 120 min and then filtered. The mixture is washed with deionized water and centrifuged 3 times. Then, it is vacuum dried at 60℃ to obtain flame-retardant organosilicon modified mica powder.

[0045] The preparation method of flame-retardant organosilicon is as follows: Under nitrogen protection, 3.9 parts by mass of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and 1.9 parts by mass of N,N-dimethylformamide are mixed, heated to 65℃, stirred for 45 min, and then 2.2 parts by mass of vinyltrimethoxysilane are added and stirred for 48 h. Then 2.2 parts by mass of 2-hydroxy-4-vinylbenzaldehyde are added and stirred for another 48 h. Finally, the mixture is washed with dichloromethane and centrifuged to obtain flame-retardant organosilicon.

[0046] The surface of the marine rubber sealing gasket has no fabric texture, and no microscopic bumps are visible under 50x magnification. When three 1.0mm gaskets are stacked and 0.01MPa pressure is applied for 10 seconds, they can be easily peeled off manually, and there are no residues on the surface of each layer. The peeling force retention rate is 93% after 10 stacking and peeling cycles. Example 3

[0047] A method for preparing a rubber sealing gasket for ships, comprising the following steps: (1) Weighing and preparing materials: 100 parts EPDM; 20 parts CIIR; 14 parts modified ethylene-α-octene copolymer; 30 parts silica; 20 parts carbon black N550; 60 parts flame retardant organosilicon modified mica powder; 15 parts paraffin oil; 5 parts zinc oxide; 2 parts stearic acid; 3.5 parts BIPB peroxide; 2 parts TAIC crosslinking agent; (2) The flame-retardant organosilicon modified mica powder, modified ethylene-α-octene copolymer and 80 parts by weight of anhydrous ethanol were mixed and sonicated for 40 min. Then, 15 parts by weight of 3M sodium hydroxide solution were added dropwise and stirred for 8 h. The dropwise addition time was controlled within 30 min. Then, the mixture was filtered, washed and dried. It was melt-blended on a two-roll mill for 7 min. The temperature of the two-roll mill was 130℃ and the rotation speed was 16 r / min to obtain mixture I. (3) Add mixture I and EPDM to a 90°C internal mixer and mix for 5 minutes. Then add zinc oxide, silica, carbon black, 1 part stearic acid and 10 parts paraffin oil in sequence and mix for 5 minutes to obtain compound A. Add CIIR to a 70°C internal mixer and mix for 5 minutes. Then add the remaining paraffin oil, zinc oxide and stearic acid and mix for 5 minutes to obtain compound B. Add compound A and compound B to a two-roll mill and mix for 5 minutes. Then add peroxide and crosslinking agent in sequence. After the powder is absorbed, alternate between triangular wrapping and rolling 8 times each to produce a sheet with a thickness of 1 mm. (4) Lay the PET release film coated with silicone oil on one side with the silicone oil side facing up on the lower hot plate of the flat vulcanizing machine. Place the unvulcanized rubber sheet on the PET release film, and then cover the unvulcanized rubber sheet with the PET release film coated with silicone oil on one side with the silicone oil side facing down. Then close the mold and vulcanize. After vulcanization, open the mold and peel off the PET release film on the unvulcanized rubber sheet to obtain the marine rubber sealing gasket. The vulcanization temperature is 170℃, the pressure is 15MPa, and the vulcanization time is 5min.

[0048] The preparation steps of the modified ethylene-α-octene copolymer are as follows: 22 parts by mass of maleic anhydride-grafted POE and 2.2 parts by mass of aminated antioxidant are melt-blended on a two-roll mill for 8 min to obtain the modified ethylene-α-octene copolymer; the temperature of the two-roll mill is 130℃ and the rotation speed is 16 r / min.

[0049] The preparation steps of the aminated antioxidant are as follows: A1. Take 1.7 parts by mass of 3-methoxy-4-hydroxyacetophenone, 2.8 parts by mass of anhydrous potassium carbonate, and 19 parts by mass of 1,2-dibromoethane and add them to 80 parts by mass of acetone. Stir and heat under reflux for 14 hours. After the reaction is complete, filter while hot and remove acetone and dibromoethane from the filtrate by vacuum distillation to obtain a solid residue. After washing and drying with distilled water, recrystallize with anhydrous ethanol to obtain bromoacetophenone. A2. Dissolve 1.2 parts by mass of 3-amino-1,2,4-triazol-5-thiol, 80 parts by mass of anhydrous ethanol, and 0.5 parts by mass of sodium hydroxide by magnetic stirring. Add 2.8 parts by mass of bromoacetophenone and reflux for 3 hours. Cool to room temperature and allow to stand. Filter, wash the solid with distilled water, dry, and place in 13.3 parts by mass of anhydrous dichloromethane. Cool to below 0°C under nitrogen protection. Add 2.7 parts by mass of trimethyliodosilane dropwise over 30 minutes. After the addition is complete, react at room temperature for 49 hours. Then add 1.3 parts by mass of methanol and continue stirring for 30 minutes. Next, remove methanol and dichloromethane by vacuum distillation. Filter, wash successively with sodium bisulfite aqueous solution, saturated sodium bicarbonate aqueous solution, and saturated brine, and dry to obtain the amino-modified antioxidant.

[0050] The preparation method of the flame-retardant organosilicon modified mica powder is as follows: 1 part by mass of sericite powder, 180 parts by mass of anhydrous ethanol and 20 parts by mass of distilled water are mixed and stirred evenly. The pH value of the mixed solution is adjusted to 4.0 with acetic acid. Then, flame-retardant organosilicon is added and left to stand for 130 min to allow for complete hydrolysis. The amount of flame-retardant organosilicon is 7% of the mass of sericite powder. Finally, the mixture is kept at 102℃ for 110 min and then filtered. The mixture is washed with deionized water and centrifuged 4 times. Then, it is vacuum dried at 60℃ to obtain flame-retardant organosilicon modified mica powder.

[0051] The preparation method of flame-retardant organosilicon is as follows: Under nitrogen protection, 4 parts by mass of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and 2 parts by mass of N,N-dimethylformamide are mixed, heated to 70℃, stirred for 30 min, and then 2.3 parts by mass of vinyltrimethoxysilane are added and stirred for 49 h. Then 2.3 parts by mass of 2-hydroxy-4-vinylbenzaldehyde are added and stirred for another 49 h. Finally, the mixture is washed with dichloromethane and centrifuged to obtain flame-retardant organosilicon.

[0052] The surface of the marine rubber sealing gasket has no fabric texture, and no microscopic bumps are visible under 50x magnification. When three 1.0mm gaskets are stacked and 0.01MPa pressure is applied for 10 seconds, they can be easily peeled off manually, and there are no residues on the surface of each layer. The peeling force retention rate is 91% after 10 stacking and peeling cycles. Example 4

[0053] The only difference between Example 4 and Example 2 is that the CIIR dosage is adjusted to 30 parts. The PET release film parameters are: substrate thickness 100μm, release force 20g / in. The surface of the marine rubber sealing gasket has no fabric texture, and no micro-bumps are visible under 50x magnification. After stacking three 1.0mm gaskets and applying 0.01MPa pressure for 10 seconds, they can be easily peeled off manually, and there are no residues on the surface of each layer. After repeated stacking and peeling 10 times, the peel force retention rate is 92%. Comparative Example 1

[0054] The only difference between Comparative Example 1 and Example 2 is that the uncured rubber sheet was obtained by directly mixing the raw material components using a conventional mixing process and then calendering it on a two-roll mill; the surface of the marine rubber gasket has no fabric texture, and no microscopic unevenness is visible under 50x magnification. When three 1.0mm gaskets are stacked and a pressure of 0.01MPa is applied for 10 seconds, they can be easily peeled off manually, and there are no residues on the surface of each layer. After repeated stacking and peeling 10 times, the peeling force retention rate is 91%. Comparative Example 2

[0055] The only difference between Comparative Example 2 and Example 2 is the composition of the marine rubber gasket: 100 parts EPDM; 20 parts CIIR; 12 parts maleic anhydride-grafted POE; 30 parts silica; 20 parts carbon black N550; 40 parts flame-retardant silicone-modified mica powder; 15 parts paraffin oil; 5 parts zinc oxide; 2 parts stearic acid; 2 parts antioxidant RD; 1 part antioxidant MB; 3.5 parts peroxide BIPB; and 2 parts crosslinking agent TAIC. The surface of the marine rubber gasket has no fabric texture, and no microscopic unevenness is visible under 50x magnification. When three 1.0mm gaskets are stacked and a pressure of 0.01MPa is applied for 10 seconds, they can be easily peeled off manually, and there are no residues on the surface of each layer. After repeated stacking and peeling 10 times, the peel force retention rate is 92%. Comparative Example 3

[0056] The only difference between Comparative Example 3 and Example 2 is the composition of the marine rubber gasket: 100 parts EPDM; 20 parts CIIR; 12 parts modified ethylene-α-octene copolymer; 30 parts silica; 20 parts carbon black N550; 40 parts silane coupling agent KH570 modified mica powder; 80 parts aluminum hydroxide; 30 parts ammonium polyphosphate; 15 parts paraffin oil; 5 parts zinc oxide; 2 parts stearic acid; 3.5 parts BIPB peroxide; and 2 parts TAIC co-crosslinking agent. The surface of the marine rubber gasket has no fabric texture, and no microscopic unevenness is visible under 50x magnification. After stacking three 1.0mm gaskets and applying a pressure of 0.01MPa for 10 seconds, they can be easily peeled off manually, with no residue on the surface of each layer. After repeated stacking and peeling 10 times, the peel force retention rate is 92%. Comparative Example 4

[0057] The only difference between Comparative Example 4 and Example 2 is the composition of the marine rubber gasket: 100 parts EPDM; 20 parts CIIR; 12 parts maleic anhydride-grafted POE; 30 parts silica; 20 parts carbon black N550; 40 parts silane coupling agent KH570 modified mica powder; 80 parts aluminum hydroxide; 30 parts ammonium polyphosphate; 15 parts paraffin oil; 5 parts zinc oxide; 2 parts stearic acid; 2 parts antioxidant RD; 1 part antioxidant MB; 3.5 parts peroxide BIPB; and 2 parts co-crosslinking agent TAIC.

[0058] The surface of the marine rubber sealing gasket has no fabric texture, and no microscopic bumps are visible under 50x magnification. When three 1.0mm gaskets are stacked and 0.01MPa pressure is applied for 10 seconds, they can be easily peeled off manually, and there are no residues on the surface of each layer. The peeling force retention rate is 91% after 10 stacking and peeling cycles. Comparative Example 5

[0059] The only difference between Comparative Example 5 and Example 2 is that conventional polyester fabric with a 300-mesh plain weave was used instead of PET release film; after vulcanization, the surface of the rubber gasket showed a clear fabric texture and a gloss of only 12 GU; the peel force test between rubbers was only 0.3 N / cm, and it was easy to slip after being stacked, and some of the polyester fabric fibers adhered to the rubber surface and were difficult to remove. Comparative Example 6

[0060] The only difference between Comparative Example 6 and Example 2 is that the PET release film used is a PET release film with a release force of 3 g / in. After vulcanization, the film is very easy to peel off, but the silicone oil on the rubber surface migrates severely, the surface energy is significantly reduced, the peel force between rubbers is only 0.1 N / cm, there is almost no self-adhesion, and it is impossible to achieve multi-layer stacking and fixation. Comparative Example 7

[0061] The only difference between Comparative Example 7 and Example 2 is that the PET release film used is a PET release film with a release force of 40 g / in; after vulcanization, the release film is difficult to peel off, and when forcibly torn off, local tears and residual glue appear on the rubber surface, the surface is damaged and cannot be used. Comparative Example 8

[0062] The only difference between Comparative Example 8 and Example 2 is that the PET release film is not coated with silicone oil on one side; after vulcanization, the rubber and PET film are completely stuck together and cannot be peeled off. Example of effect

[0063] Table 1 below shows the performance test results of the marine rubber gaskets prepared in Examples 1-4 and Comparative Examples 1-4: Table 1

[0064] Table 1 shows that the marine rubber gaskets prepared in Examples 1-4 have good mechanical properties, flame retardant properties, aging resistance properties, and surface self-adhesion properties.

[0065] The uncured rubber sheet of Comparative Example 1 was obtained by directly mixing the raw material components using a conventional mixing process and then calendering it on a two-roll mill. Compared with the marine rubber gasket prepared in Example 2, its tensile strength and aging resistance were reduced.

[0066] The marine rubber gasket of Comparative Example 2 uses maleic anhydride-grafted POE instead of the modified ethylene-α-octene copolymer of Example 2, and directly adds 2 parts of antioxidant RD and 1 part of antioxidant MB to the rubber compound. Compared with the marine rubber gasket prepared in Example 2, the tensile strength and aging resistance are reduced.

[0067] The marine rubber gasket of Comparative Example 3 uses mica powder modified with silane coupling agent KH570 instead of the flame-retardant organosilicon modified mica powder of Example 2, and contains 80 parts of aluminum hydroxide and 30 parts of ammonium polyphosphate. Compared with the marine rubber gasket prepared in Example 2, its tensile strength, aging resistance and flame retardancy are reduced.

[0068] The marine rubber gasket of Comparative Example 4 uses maleic anhydride-grafted POE instead of the modified ethylene-α-octene copolymer of Example 2, and KH570 modified mica powder instead of the flame-retardant organosilicon modified mica powder of Example 2. Additionally, 2 parts of antioxidant RD, 1 part of antioxidant MB, 80 parts of aluminum hydroxide, and 30 parts of ammonium polyphosphate are directly added to the rubber compound. Compared to the marine rubber gasket prepared in Example 2, its tensile strength and aging resistance are reduced.

[0069] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rubber sealing gasket for ships, characterized in that, When preparing the marine rubber sealing gasket, a release film is first attached to the upper and lower surfaces of the uncured rubber sheet, and then the release film is peeled off after vulcanization molding. The uncured rubber sheet comprises, by weight, the following raw material components: 100 parts EPDM rubber, 10-40 parts chlorinated butyl rubber, 11-14 parts modified ethylene-α-octene copolymer, 2-6 parts peroxide vulcanizing agent, 1-4 parts crosslinking agent, 20-60 parts reinforcing filler, 5-20 parts plasticizer, and 3-8 parts activator.

2. The marine rubber sealing gasket according to claim 1, characterized in that, The reinforcing filler includes flame-retardant organosilicon-modified mica powder.

3. The marine rubber sealing gasket according to claim 2, characterized in that, The flame-retardant organosilicon is obtained by a phosphorus hydroaddition reaction of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide with unsaturated siloxane and 2-hydroxy-4-vinylbenzaldehyde.

4. The marine rubber sealing gasket according to claim 1, characterized in that, The modified ethylene-α-octene copolymer is obtained by reacting maleic anhydride-grafted POE with an amino-containing antioxidant.

5. The marine rubber sealing gasket according to claim 1, characterized in that, The aminated antioxidant is obtained by reacting 3-methoxy-4-hydroxyacetophenone with 1,2-dibromoethane, followed by demethylation after reacting with 3-amino-1,2,4-triazol-5-thiol.

6. A method for preparing a marine rubber sealing gasket as described in any one of claims 1 to 5, characterized in that, The preparation steps include: (1) Weighing and preparing materials; (2) Mix flame-retardant organosilicon modified mica powder, modified ethylene-α-octene copolymer and 40-80 parts by weight of anhydrous ethanol, sonicate for 30-40 min, then add 10-15 parts by weight of 2-3M sodium hydroxide solution and stir for 6-8 h, with the addition time controlled within 30 min, then filter, wash and dry, and melt blend on a two-roll mill for 7-9 min, wherein the temperature of the two-roll mill is 110-130℃ and the rotation speed is 16 r / min to obtain mixture I; (3) Mix the mixture I with the remaining raw materials and then roll it into uncured rubber sheets on a two-roll mill; (4) Lay the PET release film flat on the lower hot plate of the flat vulcanizing machine, place the unvulcanized rubber sheet on the PET release film, cover the unvulcanized rubber sheet with the PET release film, then close the mold for vulcanization. After vulcanization, open the mold and peel off the PET release film on the unvulcanized rubber sheet to obtain the marine rubber sealing gasket.

7. The method for preparing a marine rubber gasket according to claim 6, characterized in that, The preparation steps of the modified ethylene-α-octene copolymer are as follows: 20-22 parts by mass of maleic anhydride-grafted POE and 1.8-2.2 parts by mass of aminated antioxidant are melt-blended on a two-roll mill to obtain the modified ethylene-α-octene copolymer; the temperature of the two-roll mill is 110-130℃ and the rotation speed is 16r / min.

8. The method for preparing a marine rubber gasket according to claim 7, characterized in that, The preparation steps of the aminated antioxidant are as follows: A1. Take 1.6-1.7 parts by weight of 3-methoxy-4-hydroxyacetophenone, 2.7-2.8 parts by weight of anhydrous potassium carbonate, and 18-19 parts by weight of 1,2-dibromoethane and add them to 79-80 parts by weight of acetone. Stir and heat under reflux for 13-14 hours. After the reaction is complete, filter while hot and remove acetone and dibromoethane from the filtrate by vacuum distillation to obtain a solid residue. After washing and drying with distilled water, recrystallize with anhydrous ethanol to obtain bromoacetophenone. A2. Dissolve 1.1-1.2 parts by weight of 3-amino-1,2,4-triazol-5-thiol, 79-80 parts by weight of anhydrous ethanol, and 0.3-0.5 parts by weight of sodium hydroxide by magnetic stirring. Add 2.6-2.8 parts by weight of bromoacetophenone and reflux for 1-3 hours. Cool to room temperature and allow to stand. Filter, wash the solid with distilled water, dry, and place in 6.6-13.3 parts by weight of anhydrous dichloromethane. Cool to below 0°C under nitrogen protection. Add 2.5-2.7 parts by weight of trimethyliodosilane dropwise over 30 minutes. After the addition is complete, react at room temperature for 47-49 hours. Then add 1.3 parts by weight of methanol and continue stirring for 10-30 minutes. Next, remove methanol and dichloromethane by vacuum distillation. Filter, wash successively with sodium bisulfite aqueous solution, saturated sodium bicarbonate aqueous solution, and saturated brine, and dry to obtain the amino-modified antioxidant.

9. The method for preparing a marine rubber gasket according to claim 6, characterized in that, The preparation method of the flame-retardant organosilicon modified mica powder is as follows: 1 part by mass of sericite powder, 144-180 parts by mass of anhydrous ethanol and 20 parts by mass of distilled water are mixed and stirred evenly. The pH value of the mixed solution is adjusted to 4.0 with acetic acid. Then, flame-retardant organosilicon is added and left to stand for 110-130 minutes to allow for complete hydrolysis. The amount of flame-retardant organosilicon is 5-7% of the mass of sericite powder. Finally, the mixture is kept at 98-102℃ for 110-130 minutes and then filtered. The mixture is washed with deionized water and centrifuged 2-4 times. Then, it is vacuum dried at 60℃ to obtain flame-retardant organosilicon modified mica powder.

10. The method for preparing a marine rubber gasket according to claim 9, characterized in that, The preparation method of the flame-retardant organosilicon is as follows: Under nitrogen protection, 3.8-4 parts by mass of 2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide and 1.8-2 parts by mass of N,N-dimethylformamide are mixed, heated to 60-70℃, stirred for 30-60 min, then 2.1-2.3 parts by mass of vinyltrimethoxysilane are added and stirred for 47-49 h, then 2.1-2.3 parts by mass of 2-hydroxy-4-vinylbenzaldehyde are added, and the stirring reaction is continued for 47-49 h. Then, the mixture is washed with dichloromethane and centrifuged to obtain the flame-retardant organosilicon.

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