Connector and method of sealing an assembly for use in a deep water environment

Abstract

The application discloses a connector and a sealing method of an assembly based on deep water environment, and belongs to the technical field of underwater electrical connection sealing. The method comprises the following steps: environment and material pretreatment, controlling the humidity of the operation environment to be less than or equal to 60%; polishing and cleaning the surfaces of the connector and the wire harness in a stepped manner; brushing a deep water special adhesion promoter; preparing a double-component water pressure resistant pouring sealant and performing vacuum defoaming treatment; sealing the connector by adopting a three-section layered pouring process, including bottom layer sealing of a needle core cavity, middle layer pouring of a connector body and full coating of a tail transition layer; gradient curing and demolding finishing. The application adopts stepped surface treatment and double-layer adhesion promoters to improve the interfacial adhesion, disperses deep water pressure stress by adopting a three-section layered pouring process, eliminates bubbles in the glue layer by combining a vacuum defoaming process, and enables the sealing structure to work stably for a long time in a deep water high pressure environment, the water pressure resistance is greater than or equal to 6 MPa, the process is simple, the cost is low, and the method can be used in fresh water / sea water and normal pressure to deep water environment.

Description

Technical Field

[0001] This invention belongs to the field of underwater electrical connection sealing technology, and relates to a sealing method for connectors and components used in deep-water environments. Background Technology

[0002] Underwater electrical connectors are widely used in marine exploration, underwater robots, offshore oil platforms, and underwater sensor networks. The sealing reliability of the connection between the connector's tail and the cable directly affects the safe operation of the entire underwater system. Currently, underwater connectors are mainly sealed using a rubber vulcanization process, which involves vulcanizing and coating the cable and contacts with rubber material to achieve a seal.

[0003] In the prior art, Chinese patent 200910304515.X discloses a deep-sealed connector, which uses vulcanized material to cover the pin contact to form a sealing body. However, this type of vulcanization process has many defects: (1) The process is complicated and requires customized metal tail parts, rubber molds and molding molds, which is not economical for small-batch and multi-variety production; (2) The equipment investment is large and requires professional equipment such as flat vulcanizing machine, vacuum vulcanizing machine and mold temperature control system, which is difficult for small and medium-sized enterprises to configure; (3) The production efficiency is low and it requires multiple processes such as preheating, mold loading, temperature control, pressure control, pressure holding vulcanization, cooling and demolding, which cannot be mass-produced quickly and cannot be installed on site; (4) The material matching requirements are extremely high. The cable sheath material, vulcanized rubber and metal surface treatment must be highly compatible, otherwise debonding and cracking will occur, and the process window is narrow. Slight deviations in temperature, pressure and time will lead to sealing failure; (5) The length and structure of the wire harness are limited. Excessively long wire harnesses or wire harnesses with multiple branches and irregular structures are difficult to adapt to vulcanization molds.

[0004] Furthermore, some existing technologies attempt to use potting compounds to replace the vulcanization process. For example, Chinese patent CN103682937A (application number 201310661357.X) discloses a potting method for the tail of a satellite cable connector, which uses a two-component epoxy resin potting compound that is stirred and degassed before potting. However, this solution is only used for sealing the tail of electrical connectors in aerospace environments and is not specifically designed for deep-water, high-pressure environments. It lacks a layered sealing structure to cope with the stress of deep-water pressure and does not address the surface treatment process of the connector-cable interface. In deep-water environments, the adhesion between the adhesive layer and the interface is insufficient, posing a risk of water leakage.

[0005] Therefore, the industry urgently needs a connector sealing method that is simple in process, low in cost, suitable for on-site construction, and can provide a long-term reliable seal in deep water and high-pressure environments. Summary of the Invention

[0006] The purpose of this invention is to provide a sealing method for connectors and components used in deep-water environments. This method achieves long-term reliable sealing under high-pressure deep-water environments through the coordinated use of environmental control, stepped surface treatment, double-layer adhesion aid, vacuum degassing of two-component adhesive, three-stage layered potting, and gradient curing processes.

[0007] The technical solution adopted in this invention is as follows:

[0008] A sealing method for connectors and components used in deep-water environments includes the following steps:

[0009] S1 Environmental and Fixture Pretreatment: Control the humidity of the working environment to ≤60%; use snap-on fixtures made of polytetrafluoroethylene, wipe with anhydrous ethanol and then air dry;

[0010] S2 Connector and Wire Harness Surface Treatment: Perform at least three levels of stepped grinding on the mating area between the cable and the connector to achieve a surface roughness Ra of 1.6~3.2μm. Then wipe clean with anhydrous ethanol at least twice and allow to air dry naturally.

[0011] S3 Adhesion promoter treatment: Apply deep water-specific adhesion promoter to the dried bonding surface in two coats, allowing it to dry for 8-12 minutes after each coat, for a total drying time of 16-24 minutes, until the surface is no longer sticky to the touch;

[0012] S4 Compound Preparation and Degassing: Weigh and mix component A and component B of the two-component water pressure resistant potting compound at a weight ratio of 1:1, stir at low speed for 5 minutes, and then perform vacuum degassing treatment for 8-12 minutes.

[0013] S5 Three-stage layered potting: The prepared potting compound is applied in three layers in sequence: the first layer is poured into the connector pin cavity to fill the gap between the solder joints; the second layer is filled into the gap between the internal cavity of the connector body and the sealing ring; the third layer covers the connector tail and the cable joint to form a gradual transition layer, and the thickness of the adhesive layer gradually decreases along the cable direction; the fastening fixture forms a sealed potting cavity.

[0014] S6 Gradient Curing: The potted connector is left to cure statically, and the curing process is vibration-free.

[0015] S7 Demolding and Finishing: Demolding without damage after curing, removing excess glue, filling defective areas with glue, and then performing secondary curing.

[0016] Furthermore, in step S2, the stepped grinding is a three-level stepped grinding, forming at least three steps from the inside to the outside along the radial direction of the cable, with each step having a consistent roughness.

[0017] Furthermore, the deep-water-specific adhesion promoter in step S3 is an amber-colored, low-viscosity liquid with a specific gravity of 0.82 g / cm³. 3(25℃), flash point -21℃; after two coats, the total drying time is 16~24 minutes, and the surface is no longer sticky.

[0018] Further, in step S4, component A is a resin / polyol composition, a black liquid with a density of 1.02 ± 0.05 g / cm³. 3 The viscosity is 2000±200 mPa·s (35℃); component B is an isocyanate prepolymer, a transparent liquid with a density of 1.04±0.05 g / cm³. 3 Viscosity 1500±200mPa·s (35℃).

[0019] Furthermore, in step S5, the third layer is formed to create a gradient adhesive layer between the cable and the connector. The thickness of the adhesive layer gradually decreases along the cable direction to disperse the stress exerted by the deep water pressure on the sealing interface.

[0020] Furthermore, in step S6, gradient curing is either room temperature curing or heated curing; room temperature curing is basically cured at 25°C for 12 hours and fully cured for 24-48 hours; heated curing is basically cured at 60°C for 2-3 hours and fully cured for 5 hours.

[0021] Furthermore, in step S1, the polytetrafluoroethylene fixture adopts a snap-on structure, which forms a sealed potting cavity after snapping. No glue overflows during the potting process, and the snap-on structure can be opened directly after curing for demolding without damage.

[0022] Furthermore, the cured potting compound has a hardness of Shore A 80±5, an elongation of >100%, and a water pressure resistance of ≥6MPa / 48h.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. A sealing method for connectors and components used in deep-water environments, which adopts a three-stage layered potting process to form a fully encapsulated, gapless sealing structure. After being immersed in 6MPa water pressure for 48 hours, there is no leakage, no bubbles, and no cracks. It can meet the requirements of atmospheric pressure to deep-sea high-pressure environments and is compatible with both freshwater and seawater media.

[0025] 2. This invention employs stepped grinding combined with a double-layer adhesive to ensure that the adhesive layer does not peel off or crack from the wire harness and connector; the tail gradient transition layer effectively disperses stress, and no cracks are found after 10,000 cycles of bending with a bending radius of 5D; it also has high environmental adaptability, with resistance to hydrolysis, salt spray (5% NaCl, 35℃, no corrosion after 168h), and good adhesion after 100 cycles of -45℃ to 100℃.

[0026] 3. This invention requires no vulcanization equipment; it can be processed on-site with only simple stirring and vacuum degassing, making it suitable for small-batch, multi-variety production. It is widely applicable to sealing requirements of different specifications for power harnesses, signal harnesses, multi-core connectors, etc. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort, wherein:

[0028] Figure 1 This is a process flow diagram of a sealing method for connectors and components used in deep-water environments;

[0029] Figure 2 This is a schematic diagram of the three-stage layered potting structure of the present invention; Attached Figure Description

[0030] 1-Connector, 2-Solder joint sealing layer, 3-Connector internal sealing layer, 4-Integrated full-coverage sealing layer, 5-Cable, 6-Connector mating end sealing ring, 7-Cable sealing ring ( Figure 2 (The black part in the middle). Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings 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 invention without inventive effort are within the scope of protection of the invention.

[0033] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0034] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0035] Example 1

[0036] This embodiment provides a sealing method for connectors and components used in deep-water environments, including the following steps:

[0037] S1: Environmental and Fixture Pretreatment: Select an indoor working environment with relative humidity ≤60% under room temperature conditions, and ensure the environment is free of corrosive gases and oil stains; prepare a snap-on potting fixture made of polytetrafluoroethylene (PTFE), wipe the inner surface of the fixture with anhydrous ethanol to remove surface residues, and let it dry for more than 5 minutes before use; the low surface energy characteristics of PTFE material ensure that the cured colloid will not stick to the fixture, and the snap-on structure facilitates quick opening and closing operations;

[0038] S2: Surface treatment of connectors and wire harnesses: The joint between the cable and the connector is subjected to a three-level stepped grinding process; specifically, three steps are formed from the inside to the outside along the radial direction of the cable. The first step is located on the end face of the cable sheath, the second step is located in the overlapping area of ​​the cable sheath and the connector housing, and the third step is located on the surface of the connector housing; the surface roughness Ra of the three steps after grinding is 1.6~3.2μm; after grinding, the ground area is wiped clean twice with anhydrous ethanol and allowed to air dry for ≥5 minutes to ensure that the surface is free of dust, water, oil and oxide layer.

[0039] S3: Adhesive Treatment: Apply a first coat of deep-water adhesive evenly to the dried bonding surface. This adhesive is an amber-colored, low-viscosity liquid with a specific gravity of 0.82 g / cm³ (25℃) and a flash point of -21℃. By mass fraction, it is a mixture of 3.0% Silquest® A-1128 silane coupling agent, 52.0% n-hexane, 43.0% methyl formate, and 2.0% diethyl ether, which can increase the adhesive strength between the subsequent potting compound and the substrate by approximately 80%. After application, allow it to dry for 10 minutes, then apply a second coat and allow it to dry for another 10 minutes, for a total drying time of 20 minutes, until the surface is no longer tacky. Replace the cap immediately after use to prevent the adhesive from evaporating.

[0040] S4: Compound Formulation and Degassing: Weigh component A and component B of the two-component water pressure resistant potting compound in a 1:1 weight ratio; component A is a resin / polyol composition, in the form of a black liquid with a density of 1.02±0.05 g / cm³. 3 The viscosity of component A is 2000±200 mPa·s (35℃); component B is an isocyanate prepolymer, a transparent liquid with a density of 1.04±0.05 g / cm³ and a viscosity of 1500±200 mPa·s (35℃). Both components are poured into a mixing container and stirred at low speed for 5 minutes, scraping the sides and bottom during this process to ensure no sedimentation, particles, or stratification. The mixed compound is then placed in a vacuum degassing device and degassed for 10 minutes under a vacuum of ≤-0.095 MPa to essentially eliminate microbubbles. The workable time of the prepared compound at 25℃ / 100g is approximately 30 minutes.

[0041] Component A, by weight, was prepared as follows: 35.0 parts of polyether polyol A, 20.0 parts of polyether polyol B, 15.0 parts of polytetrahydrofuran diol, and 12.0 parts of castor oil polyol were sequentially added to a stainless steel reactor.

[0042] Start stirring at 120 r / min; heat to 120℃, evacuate to a vacuum degree ≤ -0.095 MPa, and maintain this temperature for 3 h to dehydrate until the moisture content is ≤ 0.05%; cool to 60-70℃, release the vacuum, and purge with dry nitrogen for protection to obtain a polyol premix; preheat 6.0 parts of 1,4-butanediol and 3.0 parts of trimethylolpropane in a 60-70℃ water bath until completely melted; under nitrogen protection, add the molten 6.0 parts of 1,4-butanediol and 3.0 parts of trimethylolpropane to the above polyol premix, heat to 80-85℃, stir for 30-40 min, cool to 50-60℃, and maintain a vacuum degree ≤ -0.08 MPa and a stirring speed of 30-50 r / min. Under the condition of r / min, a mixed powder premixed from 3.0 parts of carbon black, 2.5 parts of nano-fumed silica, and 1.8 parts of nano-calcium carbonate was added in three batches. After each addition, the mixture was stirred for 15-20 minutes, scraping the walls and bottom of the container. After all the powder was added, the temperature was raised to 80℃ and the mixture was vacuum stirred for 80 minutes.

[0043] Cool to 40-50℃, and under nitrogen protection, add 0.15 parts of dibutyltin laurylate, 0.30 parts of bismorpholino diethyl ether, 0.50 parts of BYK-088, 0.50 parts of TEGO Wet KL 245, 0.25 parts of Stabaxol P, 0.30 parts of Irganox 1010, 0.20 parts of UV-320, and 0.30 parts of 3A molecular sieve powder in sequence. Stir for 10-15 minutes after each addition before adding the next addition. After all additions are completed, maintain a vacuum of ≤-0.095 MPa, stir for 40 minutes, filter, and degas to obtain component A.

[0044] S5: Three-stage layered filling: Refer to Figure 2 The structure shown involves applying three layers of potting compound: the first layer (solder joint sealing layer 2) involves filling the bottom of the connector 1's pin core cavity with potting compound, filling the gaps between the solder joints, and ensuring the solder joints are completely covered by the compound to prevent short circuits and water leakage; the second layer (connector internal sealing layer 3) involves filling the connector body's internal cavity with potting compound, filling the gap between the shell and the sealing rings (including the connector mating end sealing ring 6 and the cable sealing ring 7), forming the main sealing barrier; the third layer (integrated full-coverage sealing layer 4) involves covering the connector tail and the junction with the cable 5 with potting compound, forming a gradually decreasing thickness transition layer along the cable direction, gradually transitioning the deep water pressure stress from the rigid sealing interface to the flexible cable body, reducing stress concentration; after the three layers of potting are completed, the PTFE snap-fit ​​fixture is fastened to form a sealed potting cavity, preventing glue overflow during the potting process;

[0045] S6: Gradient Curing: Allow the potted connector to cure statically at room temperature (25°C) without vibration during the curing process; the basic curing time is 12 hours, and the complete curing time is 24-48 hours; during the colloid curing process, a slow curing reaction helps to expel residual air and avoid bubble defects; if it is necessary to shorten the work cycle, it can be cured at 60°C, with a basic curing time of 2-3 hours and a complete curing time of 5 hours;

[0046] S7: Demolding and Finishing: After curing, open the snap-fit ​​structure of the PTFE fixture for non-destructive demolding; trim the edges of the demolded sealant to remove excess glue and burrs; inspect the surface of the adhesive layer, fill any defects with glue, and then perform a second curing; finally, conduct an initial inspection of the appearance and seal, and transfer the finished product to the warehouse after confirming that there are no defects.

[0047] Sealing performance verification: The following performance tests were performed on the deep-water connector sealing assembly prepared using the method of this embodiment:

[0048] (1) Deep water high pressure sealing test: Immersed in 6MPa water pressure for 48h, the result was no leakage, no bubbles, no cracks, and the insulation resistance was >100MΩ;

[0049] (2) High and low temperature cycle test: 100 cycles within the temperature range of -45℃ to 100℃, the adhesion is intact and the seal is 100% effective;

[0050] (3) Salt spray test: 5% NaCl solution, 35℃ for 168h, no corrosion, no debonding, and stable insulation;

[0051] (4) Cable bending test: After 10,000 reciprocating bends under a bending radius of 5D, the adhesive layer showed no cracks and the seal did not fail.

[0052] (5) Long-term immersion test: After continuous immersion in seawater / fresh water for 180 days, there is no water leakage or performance degradation.

[0053] Example 2

[0054] This embodiment, based on Embodiment 1, employs a heat curing method and makes adaptive adjustments for multi-branch irregularly shaped wire harnesses. Specifically:

[0055] S6 (Cure): Place the potted connector in a 60°C oven for static curing, using a gradient heating method: first hold at 40°C for 1 hour, then increase to 60°C and hold for 2.5 hours, for a total curing time of 5 hours. Gradient heating helps to expel residual air and reduce bubble defects; this embodiment can be used in deep-water connector sealing operations that require rapid delivery, such as on-site repairs on offshore platforms.

[0056] Wiring harness structure: Designed for a Y-type deep-water connector with three branch cables, the main cable is φ12mm and the branch cables are φ6mm. The PTFE fixture adopts a split snap-fit ​​structure to fit the geometry of the main cable and branches respectively; during potting, the joint between the main cable and the connector is first potted with three layers, and then the root of each branch is individually covered with a third layer of gradient transition coating, so that all branch interfaces form a stress-dispersing structure.

[0057] Sealing performance verification:

[0058] (1) Deep water high pressure sealing test: Immersed in 4MPa water pressure for 48h, no leakage, no bubbles, no cracks;

[0059] (2) Cable bending test: Each branch was bent with a bending radius of 5D for 5000 cycles, and the adhesive layer showed no cracks.

[0060] (3) Salt spray test: 5% NaCl, 35℃, 168h no corrosion.

[0061] This embodiment demonstrates that the method can be used for multi-branch irregular wire harness structures that are difficult to process in the vulcanization process, and it has good versatility.

[0062] Example 3

[0063] This embodiment, based on Embodiment 1, adjusts the surface treatment process to adapt to shallow to medium water environments (water pressure ≤ 3MPa), further simplifying the process and reducing costs; specifically:

[0064] S2 (Surface Treatment): A two-stage stepped polishing process (instead of a three-stage process) is used, with the roughness Ra controlled within the range of 2.0~3.2μm. The first-stage stepped surface is located on the cable sheath end face, and the second-stage stepped surface is located on the connector housing surface;

[0065] S3 (Adhesive Treatment): Apply the adhesive only once, let it dry for 15 minutes, and then proceed with potting.

[0066] The remaining steps are the same as in Example 1.

[0067] Sealing performance verification:

[0068] (1) Deep water high pressure sealing test: Immersed in 3MPa water pressure for 48h, no leakage, no bubbles, no cracks, insulation resistance >100MΩ;

[0069] (2) Cable bending test: bending radius 5D, 5000 reciprocating bends, no cracks in the adhesive layer;

[0070] (3) Salt spray test: 5% NaCl, 35℃, 168h no corrosion.

[0071] This embodiment can be used in shallow to medium water environments with relatively low sealing requirements (such as water depths of less than 300 meters). While maintaining basic sealing performance, it further simplifies the process and reduces material and labor costs.

[0072] Comparative Example 1

[0073] The surface was polished in one pass using ordinary sandpaper, achieving a surface roughness Ra≈0.8μm. The remaining steps were the same as in Example 1. After a 6MPa / 48h water pressure test, significant water seepage was observed at the connector-cable interface, and the insulation resistance dropped to <10MΩ. This indicates that the mechanical interlocking force created by the stepped polishing is a necessary condition to resist high-pressure water seepage.

[0074] Comparative Example 2

[0075] The third layer uses a uniform thickness coating (without gradient), and the remaining steps are the same as in Example 1. After 3000 reciprocating bends with a bending radius of 5D, an annular crack appeared in the adhesive layer at the junction of the connector tail and the cable. When bending continued for 5000 times, the crack expanded to penetrate, and the seal failed. This indicates that the gradient transition layer plays an important role in dispersing bending stress.

[0076] Comparative Example 3

[0077] In step S4, the vacuum degassing process was omitted; the needle was directly filled after low-speed stirring for 5 minutes, and the remaining steps were the same as in Example 1. After a 6MPa / 48h water pressure test, the seal was disassembled, and microbubbles were found inside the needle core cavity, with an insulation resistance of <10MΩ, indicating a risk of short circuit. This demonstrates that vacuum degassing plays an important role in eliminating microbubbles and maintaining the reliability of the needle core cavity seal.

[0078] Comparative Example 4

[0079] In step S3, only one coat of adhesive was applied and the drying time was shortened to 8 minutes before potting. The remaining steps were the same as in Example 1. After a 6MPa / 48h water pressure test, localized debonding occurred at the interface between the connector housing and the adhesive layer, with a peel strength decrease of approximately 60%. This indicates that the double-layer adhesive treatment plays an irreplaceable role in improving the adhesion of interfaces under deep water and high pressure.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sealing method for connectors and components used in deep-water environments, characterized in that: Includes the following steps: S1 Environmental and Fixture Pretreatment: Control the humidity of the working environment to ≤60%; use snap-on fixtures made of polytetrafluoroethylene, wipe with anhydrous ethanol and then air dry; S2 Connector and Wire Harness Surface Treatment: Perform at least three levels of stepped grinding on the mating area between the cable and the connector to achieve a surface roughness Ra of 1.6~3.2μm. Then wipe clean with anhydrous ethanol at least twice and allow to air dry naturally. S3 Adhesion promoter treatment: Apply deep water-specific adhesion promoter to the dried bonding surface in two coats, allowing it to dry for 8-12 minutes after each coat, for a total drying time of 16-24 minutes, until the surface is no longer sticky to the touch; S4 Compound Preparation and Degassing: Weigh and mix component A and component B of the two-component water pressure resistant potting compound at a weight ratio of 1:1, stir at low speed for 5 minutes, and then perform vacuum degassing treatment for 8-12 minutes. S5 Three-stage layered potting: The prepared potting compound is applied in three layers in sequence: the first layer is poured into the connector pin cavity to fill the gap between the solder joints; the second layer is filled into the gap between the internal cavity of the connector body and the sealing ring; the third layer covers the connector tail and the cable joint to form a gradual transition layer, and the thickness of the adhesive layer gradually decreases along the cable direction; the fastening fixture forms a sealed potting cavity. S6 Gradient Curing: The potted connector is left to cure statically, and the curing process is vibration-free. S7 Demolding and Finishing: Demolding without damage after curing, removing excess glue, filling defective areas with glue, and then performing secondary curing.

2. The sealing method for connectors and components used in deep-water environments according to claim 1, characterized in that: In step S2, the stepped grinding is a three-level stepped grinding, forming at least three steps from the inside to the outside along the radial direction of the cable, with each step having the same roughness.

3. The sealing method for connectors and components used in deep-water environments according to claim 1, characterized in that: In step S3, the specific gravity of the deep-water-specific adhesion promoter is 0.82 g / cm³. 3 Flash point -21℃; after two coats, the total drying time is 16~24 minutes, until the surface is no longer sticky.

4. A sealing method for connectors and components used in deep-water environments according to claim 1, characterized in that: In step S4, component A is a resin / polyol composition with a density of 1.02 ± 0.05 g / cm³. 3 The viscosity is 2000±200 mPa·s; component B is an isocyanate prepolymer, a transparent liquid with a density of 1.04±0.05 g / cm³ and a viscosity of 1500±200 mPa·s.

5. A sealing method for connectors and components used in deep-water environments according to claim 1, characterized in that: In step S5, the third layer is formed to create a gradient adhesive layer between the cable and the connector. The thickness of the adhesive layer gradually decreases along the cable direction to disperse the stress exerted by the deep water pressure on the sealing interface.

6. A sealing method for connectors and components used in deep-water environments according to claim 1, characterized in that: In step S6, gradient curing can be either room temperature curing or heated curing; room temperature curing is basically cured at 25°C for 12 hours and fully cured for 24-48 hours; heated curing is basically cured at 60°C for 2-3 hours and fully cured for 5 hours.

7. A sealing method for connectors and components used in deep-water environments according to claim 1, characterized in that: In step S1, the polytetrafluoroethylene fixture adopts a snap-on structure, which forms a sealed potting cavity after being snapped on. No glue overflows during the potting process, and the snap-on structure can be opened directly after curing for demolding without damage.

8. A sealing method for connectors and components used in deep-water environments according to claim 1, characterized in that: The cured potting compound has a hardness of Shore A 80±5, an elongation of >100%, and a water pressure resistance of ≥6MPa / 48h.

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