An environmentally friendly antifouling slow-release material and its preparation method and application

Abstract

The present invention relates to the field of antifouling technology, and provides an environmentally friendly antifouling slow-release material, a preparation method thereof, and an application thereof. The present invention first modifies montmorillonite with hydrochloric acid, and then utilizes the interlayer adsorption principle to load an environmentally friendly antifouling agent into the interior of the acid-modified montmorillonite to prepare a nano-composite slow-release material, and then incorporates the prepared nano-composite slow-release material into a polyethylene material, and prepares the environmentally friendly antifouling slow-release material by compression molding. The antifouling slow-release material prepared by the present invention is non-toxic and pollution-free, and can achieve the effect of slow release of the antifouling agent. The antifouling slow-release material of the present invention is assembled into an ocean sensor, which can avoid marine microorganisms attached around the sensor, reduce the phenomenon of reduced sensor sensitivity caused by marine biological fouling, protect it from damage by the surrounding environment for a long time, and extend the service life of the sensor. The preparation method provided by the present invention is simple to operate, does not require the use of toxic reagents, and has low cost.

Description

Technical Field

[0001] The present invention relates to the field of antifouling technology, and in particular to an environmentally friendly antifouling slow-release material and a preparation method and application thereof. Background Art

[0002] The scientific and rational development of marine resources is essential for the sustainable development of the marine economy. Marine environmental monitoring can maximize the protection of the marine environment from pollution and provide a safe living environment for marine life. At the same time, strengthening marine environmental monitoring can provide monitoring data for the development of marine energy and other fields.

[0003] Seawater quality is typically assessed through measurements of parameters such as pH, dissolved oxygen, total salinity, temperature, and conductivity. However, the marine environment is a highly corrosive one. In addition to electrochemical corrosion caused by seawater, biofouling corrosion caused by the growth of marine organisms and their metabolites is also a significant risk. In real-world marine environments, sensors used to measure these parameters can be susceptible to biofouling, significantly reducing their sensitivity and service life, and increasing maintenance costs.

[0004] To protect sensors from biofouling, they are typically fitted with anti-biofouling kits. This prevents the growth of marine organisms in sensor piping and water inlets, thereby extending the sensor's service life. Currently used antifouling agents are organotin systems, which are highly toxic and environmentally unfriendly. Furthermore, these kits are typically mixed with engineering plastics and then compression molded, or soaked in an antifouling solution, resulting in rapid release of the antifouling agent and a shorter service life. Therefore, there is an urgent need for environmentally friendly, slow-release antifouling components that meet the requirements of marine sensors. Summary of the Invention

[0005] In light of this, the present invention provides an environmentally friendly antifouling slow-release material, its preparation method, and its application. The environmentally friendly, slow-release antifouling agent releases slowly, enabling long-term protection of ocean sensors, reducing sensor sensitivity reduction due to marine biofouling and extending their service life.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A method for preparing an environmentally friendly antifouling slow-release material comprises the following steps:

[0008] Modifying montmorillonite with hydrochloric acid to obtain acid-modified montmorillonite;

[0009] The acid-modified montmorillonite, water and an antifouling agent are mixed and subjected to liquid phase intercalation to obtain an antifouling agent-montmorillonite nanocomposite sustained-release material; the antifouling agent is one or more of capsaicin, camptothecin and 4,5-dichloro-N-octyl-4-isothiazoline-3-one;

[0010] The antifouling agent-montmorillonite nanocomposite slow-release material is mixed with polyethylene and subjected to compression molding to obtain the environmentally friendly antifouling slow-release material.

[0011] Preferably, the hydrochloric acid modification comprises: dispersing the montmorillonite in a hydrochloric acid solution and heating and stirring; the concentration of the hydrochloric acid solution is 0.1 to 5 mol / L.

[0012] Preferably, the heating and stirring is carried out at a temperature of 70 to 90° C. and for a time of 0.5 to 24 hours.

[0013] Preferably, the mass ratio of the acid-modified montmorillonite to the antifouling agent is (0.5-2):(0.5-5).

[0014] Preferably, the temperature of the liquid phase intercalation is 60-90° C., and the time is 24-32 hours; and the liquid phase intercalation is carried out under stirring conditions.

[0015] Preferably, the polyethylene is high-density polyethylene; the mass ratio of the antifouling agent-montmorillonite nanocomposite sustained-release material to the polyethylene is (1-8):(1-25).

[0016] Preferably, the compression molding includes: mixing the antifouling agent-montmorillonite nanocomposite sustained-release material and polyethylene and adding the mixture to a mold, heating and pressurizing the mold containing the mixture in sequence; the heating temperature is 150-180°C, and the holding time is 0.5-4h; the pressurizing pressure is 5-40MPa, and the holding time is 10-30s.

[0017] The present invention also provides an environmentally friendly antifouling slow-release material prepared by the preparation method described in the above scheme, comprising polyethylene and an antifouling agent-montmorillonite nanocomposite slow-release material dispersed in the polyethylene, wherein the antifouling agent-montmorillonite nanocomposite slow-release material comprises acid-modified montmorillonite and an antifouling agent loaded between the acid-modified montmorillonite layers.

[0018] The present invention also provides the use of the environmentally friendly antifouling slow-release material described in the above solution in ocean sensors.

[0019] Preferably, the ocean sensor comprises a CTD conductivity sensor.

[0020] The present invention provides a method for preparing an environmentally friendly antifouling slow-release material, comprising the following steps: modifying montmorillonite with hydrochloric acid to obtain acid-modified montmorillonite; mixing the acid-modified montmorillonite, water, and an antifouling agent for liquid-phase intercalation to obtain an antifouling agent-montmorillonite nanocomposite slow-release material; the antifouling agent is one or more of capsaicin, camptothecin, and 4,5-dichloro-N-octyl-4-isothiazolin-3-one; mixing the antifouling agent-montmorillonite nanocomposite slow-release material with polyethylene for compression molding to obtain the environmentally friendly antifouling slow-release material. The present invention first modifies the montmorillonite with hydrochloric acid to increase its interlamellar spacing, thereby improving its loading capacity for the antifouling agent; then, utilizing the interlamellar adsorption principle, the environmentally friendly antifouling agent is loaded into the interior of the acid-modified montmorillonite to prepare a nanocomposite slow-release material; then, the prepared nanocomposite slow-release material is incorporated into a polyethylene material, and an environmentally friendly antifouling slow-release material with a corresponding structure is prepared by compression molding. The antifouling agent used in the present invention is one or more of the environmentally friendly capsaicin, camptothecin and 4,5-dichloro-N-octyl-4-isothiazoline-3-one (DCOIT), avoiding the use of organotin. The resulting antifouling slow-release material is non-toxic and pollution-free. In addition, the present invention loads the antifouling agent into montmorillonite, which can control the release rate of the antifouling agent between layers and achieve a slow release effect. When the antifouling slow-release material of the present invention is assembled into an ocean sensor, it can repel marine microorganisms attached to the periphery of the sensor, reduce the phenomenon of reduced sensor sensitivity caused by marine biofouling, protect the sensor from damage by the surrounding environment for a long time, and extend the service life of the sensor.

[0021] The preparation method provided by the present invention is simple to operate, does not require the use of toxic reagents, and is low-cost. Currently, antifouling materials used in ocean sensors are typically imported, which not only has a long lead time but is also expensive. Using the antifouling slow-release material of the present invention can reduce costs, address the import dependency issue, and meet market demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a CTD conductivity sensor;

[0023] Figure 2 This is a physical picture of the imported antifouling material used in Example 2;

[0024] Figure 3 This is the appearance of the recycled CTD conductivity sensor OST35M-22023;

[0025] Figure 4 The conductivity measurement data of four CTD conductivity sensors. DETAILED DESCRIPTION

[0026] The present invention provides a method for preparing an environmentally friendly antifouling slow-release material, comprising the following steps:

[0027] Modifying montmorillonite with hydrochloric acid to obtain acid-modified montmorillonite;

[0028] The acid-modified montmorillonite, water and an antifouling agent are mixed and subjected to liquid phase intercalation to obtain an antifouling agent-montmorillonite nanocomposite sustained-release material; the antifouling agent is one or more of capsaicin, camptothecin and 4,5-dichloro-N-octyl-4-isothiazoline-3-one;

[0029] The antifouling agent-montmorillonite nanocomposite slow-release material is mixed with polyethylene and subjected to compression molding to obtain the environmentally friendly antifouling slow-release material.

[0030] The present invention modifies montmorillonite with hydrochloric acid to obtain acid-modified montmorillonite. In the present invention, the montmorillonite is a lamellar nanomaterial. The hydrochloric acid modification preferably comprises: dispersing the montmorillonite in a hydrochloric acid solution and heating and stirring. The heating and stirring temperature is preferably 70-90°C, more preferably 75-85°C, and the heating and stirring time is preferably 0.5-24 hours, more preferably 5-12 hours, and even more preferably 10 hours. The heating and stirring speed is preferably 500-1000 r / min. The concentration of the hydrochloric acid solution is preferably 0.1-5 mol / L, more preferably 0.5-2 mol / L, and even more preferably 1 mol / L. The present invention has no particular requirements for the amount of hydrochloric acid solution used; it only requires that the montmorillonite be submerged. In a specific embodiment of the present invention, the montmorillonite is preferably first dispersed in the hydrochloric acid solution to form a suspension, and then heated and stirred in a water bath. After the heating and stirring is completed, the resulting liquid is preferably filtered, and the resulting solid product is dried to obtain the acid-modified montmorillonite. The present invention modifies montmorillonite with hydrochloric acid, thereby increasing the interlamellar spacing of the montmorillonite and further improving its loading performance for the antifouling agent.

[0031] After obtaining the acid-modified montmorillonite, the present invention mixes the acid-modified montmorillonite, water, and an antifouling agent for liquid-phase intercalation to obtain an antifouling agent-montmorillonite nanocomposite sustained-release material. In the present invention, the antifouling agent is one or more of capsaicin, camptothecin, and 4,5-dichloro-N-octyl-4-isothiazolin-3-one, more preferably capsaicin; the mass ratio of the acid-modified montmorillonite to the antifouling agent is preferably (0.5-2):(0.5-5), more preferably (0.5-1):(1-2), and even more preferably 1:1; the amount ratio of the acid-modified montmorillonite to water is preferably 0-1 g:100-150 mL, and the amount of acidic montmorillonite is not zero.

[0032] In the present invention, the temperature of the liquid-phase intercalation is preferably 60-90°C, more preferably 70-80°C, and the time is preferably 24-32 hours; the liquid-phase intercalation is preferably carried out under stirring. In a specific embodiment of the present invention, it is preferred to first disperse the acid-modified montmorillonite in water to form a suspension, place the suspension in a water bath, and stir and heat it to 60-90°C. Then, the antifouling agent is added to the suspension and stirred at 60-90°C for 24-32 hours. The antifouling agent is loaded into the interlayers of the montmorillonite by the liquid-phase intercalation method, thereby achieving a slow release effect.

[0033] After the liquid phase intercalation is completed, the present invention preferably centrifuges and washes the obtained product liquid, and grinds the obtained solid product after drying to obtain the antifouling agent-montmorillonite nanocomposite sustained-release material; the drying temperature is preferably 40 to 90° C., and the drying time is preferably 10 to 24 hours; the antifouling agent-montmorillonite nanocomposite sustained-release material specifically includes acid-modified montmorillonite and an antifouling agent loaded between the acid-modified montmorillonite layers; the mass fraction of the antifouling agent in the antifouling agent-montmorillonite nanocomposite sustained-release material is preferably 32%.

[0034] After obtaining the antifouling agent-montmorillonite nanocomposite slow-release material, the present invention mixes the antifouling agent-montmorillonite nanocomposite slow-release material with polyethylene and performs compression molding to obtain the environmentally friendly antifouling slow-release material. In the present invention, the polyethylene is preferably high-density polyethylene, specifically high-density polyethylene powder. The present invention has no special requirements for the particle size of the high-density polyethylene powder, and any particle size familiar to those skilled in the art can be used. The mass ratio of the antifouling agent-montmorillonite nanocomposite slow-release material to polyethylene is preferably (1-8):(1-25), more preferably (5-7):(2-24), and even more preferably 1:4.

[0035] In the present invention, the compression molding process preferably includes: mixing the antifouling agent-montmorillonite nanocomposite slow-release material and polyethylene and adding the mixture to a mold, and sequentially heating and pressurizing the mold containing the mixture; the heating temperature is preferably 150-180°C, more preferably 160-170°C, the heating holding time is preferably 0.5-4 hours, and the heating is preferably performed in a heating furnace; the pressurizing pressure is preferably 5-40 MPa, and the holding time is preferably 10-30 seconds, more preferably 20 seconds. In the present invention, the antifouling slow-release material obtained after compression molding is specifically an antifouling slow-release part for assembly into an ocean sensor. The present invention has no requirements for the shape of the mold, and the mold can be designed according to the shape of the target part.

[0036] The present invention addresses the problems of reduced sensitivity, decreased measurement capability, and shortened lifespan of ocean sensors caused by the attachment of surrounding marine organisms. Based on the nano-container effect of montmorillonite, the present invention utilizes a liquid phase intercalation method to load an environmentally friendly antifouling agent into the interlayers of acid-modified montmorillonite to prepare a nano-composite sustained-release material, which is then incorporated into polyethylene powder. A molding method is used to prepare an environmentally friendly antifouling sustained-release material with a corresponding structure for ocean sensors, thereby achieving long-term release of the antifouling agent to protect the sensor.

[0037] The present invention also provides an environmentally friendly antifouling slow-release material prepared by the preparation method described in the above scheme, comprising polyethylene and an antifouling agent-montmorillonite nanocomposite slow-release material dispersed in the polyethylene. The antifouling agent-montmorillonite nanocomposite slow-release material comprises acid-modified montmorillonite and an antifouling agent loaded between the acid-modified montmorillonite layers. The present invention has no particular requirements for the specific shape of the environmentally friendly antifouling slow-release material; it can be configured according to the structure of the target ocean sensor to match the structure of the area of ​​the ocean sensor where the antifouling slow-release material is to be mounted.

[0038] The present invention also provides the application of the environmentally friendly anti-fouling slow-release material described in the above scheme in ocean sensors; in the present invention, the ocean sensor preferably includes a CTD conductivity sensor; when the ocean sensor is preferably a CTD conductivity sensor, the environmentally friendly anti-fouling slow-release material is preferably a circular ring-shaped part. The present invention has no special requirements for the size of the circular ring-shaped part, and it can be designed according to the size of the protected ocean sensor; the circular ring-shaped environmentally friendly anti-fouling slow-release material is specifically assembled one at the water inlet and outlet of the CTD conductivity sensor.

[0039] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] Example 1

[0041] The montmorillonite was dispersed in a 1 mol / L hydrochloric acid solution to form a suspension. The suspension was placed in a stirrable water bath and stirred at 80° C. for 10 h at a stirring speed of 1000 r / min. After the stirring was completed, the suspension was filtered and dried to obtain an acid-modified montmorillonite powder.

[0042] 1 g of acid-modified montmorillonite powder was dispersed in 100 mL of water to form a suspension, which was stirred and heated to 80°C in a water bath. Capsaicin was then added in a mass ratio of capsaicin to acid-modified montmorillonite of 1:1. The suspension was stirred at 80°C for 24 hours, and the antifouling agent was loaded into the montmorillonite interlayer using a liquid phase intercalation method. After stopping stirring and heating, the resulting product liquid was centrifuged and washed, and the solid product was dried at 60°C for 24 hours. After grinding, a capsaicin-montmorillonite nanocomposite sustained-release material was obtained, in which the capsaicin loading amount was 32%.

[0043] The capsaicin-montmorillonite nanocomposite sustained-release material and high-density polyethylene powder were mixed evenly in a mass ratio of 1:4, and then added to a mold. The mold containing the mixture was placed in a heating furnace and kept warm at 160°C for 4 hours. After that, it was taken out and pressurized with a pressure of 40 MPa and a holding time of 20 seconds. After demolding, an environmentally friendly anti-fouling sustained-release material was obtained. The material was in a circular shape and its size matched the water inlet and outlet of the CTD conductivity sensor model OST35M used in Example 2. The specific dimensions were: outer diameter 17 mm, inner diameter 7 mm, and length 10 mm.

[0044] Example 2

[0045] The environmentally friendly antifouling slow-release material prepared in Example 1 was assembled to the water inlet and outlet ends of the CTD conductivity sensor. The assembly position of the CTD conductivity sensor was as follows: Figure 1 As shown, the model of the CTD conductivity sensor is OST35M and the serial number is 22023 (recorded as OST35M-22023).

[0046] In addition, two CTD conductivity sensors of model SBE37SM were taken, numbered 5499 and 5500 respectively (recorded as SBE37SM-5499 and SBE37SM-5500), and one CTD conductivity sensor of model OST35M was taken, numbered 22025 (recorded as OST35M-22025). SBE37SM-5499 was equipped with an imported anti-fouling material (engineering material of tributyltin oxide, in which the content of tributyltin oxide was 53%) at the water inlet and outlet. Figure 2 This is a photo of imported antifouling materials. SBE37SM-5500 and OST35M-22025 are not treated with antifouling. Specific parameters are shown in Table 1.

[0047] Table 1 Models and parameters of CTD conductivity sensors

[0048]

[0049] The antifouling test is as follows:

[0050] Research on the mechanisms of marine biofouling indicates that marine biofouling is most severe in the summer, when water depths are less than 10 meters and current velocities are less than 1.4 m / s. The environmentally friendly antifouling slow-release material prepared in Example 1 was evaluated for its antifouling performance, referring to "GBT 5370-2007 Shallow Sea Immersion Test Method for Antifouling Paint Samples." This evaluation determined that the electrodes were considered effective if they showed no biofouling after a minimum of three months of service in this environment.

[0051] In summary, the experimental site was selected as the nearshore experimental platform of Hainan University. Since Hainan has vigorous biological growth throughout the year, the service period can be no less than 3 months, and there is no need to limit it to a special period. The experimental platform is a shore floating bridge with a maximum water depth of 4m. Hanging on the floating bridge can ensure that the immersion depth remains unchanged, and the hanging water depth is 2m to prevent the prototype from touching the bottom. The location is on the shore of the dock, there is no wind and waves, and the environmental flow rate does not exceed 1.4m / s, which meets the experimental requirements.

[0052] Because this material is used in CTD conductivity sensors, further evaluation of its antifouling effectiveness requires CTD measurement data. This involves comparing laboratory temperature and salinity test data before and after the CTD sea trials to assess its antifouling effectiveness. A lack of significant drift indicates good antifouling effectiveness. The instrument's monthly stability is 0.003mS / cm. This is multiplied by the operating time. For example, taking four months as an example, the theoretical drift before and after sea trials should be less than 0.012mS / cm. However, in practice, other contaminants can cause sensor drift. This threshold can be extended to 0.015mS / cm. This means that after sea trials, laboratory conductivity re-measurements with an indication error of less than 0.015mS / cm are considered acceptable.

[0053] Before the sea trial, the conductivity sensors on the four test machines were calibrated. After powering on, they were installed on the mounting bracket. The bracket was suspended from the pontoon at Hainan University's experimental dock using a Kevlar rope. A mark was made 2 meters above the rope. After lowering the rope until the mark was submerged, the rope end was secured to the pontoon pile.

[0054] Hainan University professionals regularly observe the species, abundance, and proliferation of marine fouling organisms attached to the prototype, taking photos and keeping records. They also briefly rinse the conductivity sensor to prevent sediment accumulation that could affect measurements. At the end of the observation period, the fixture is brought ashore, photographed, and immediately rinsed with clean water to prevent any dead organisms from becoming difficult to remove.

[0055] After the sea trial is completed, all the tested instruments will be returned to the laboratory for data playback and processing, and conductivity retest experiments will be conducted to evaluate their anti-fouling effects.

[0056] Figure 3 This is the appearance of the CTD conductivity sensor OST35M-22023 after recycling. Figure 3It can be seen that the CTD conductivity sensor has serious biological adhesion on the outside, while the inside is basically free of biological adhesion due to the anti-fouling slow-release material of the present invention, indicating that the anti-fouling slow-release material of the present invention can have a good protective effect on the CTD sensor.

[0057] Figure 4 The conductivity measurement data of 4 CTD conductivity sensors. Figure 4 As can be seen from the data, the two CTD conductivity sensors (SBE37SM-5499 and OST35M-22023) installed with anti-fouling materials have a good anti-fouling effect, and the conductivity measurement data has not shown a downward trend (the overall decline in the test curve in the figure is caused by the decrease in temperature and has nothing to do with whether there is anti-fouling material). However, the conductivity test data of the two CTD conductivity sensors that have not undergone anti-fouling treatment are significantly lower, indicating that they have been affected by biofouling.

[0058] Table 2 shows the laboratory retest data for four CTD conductivity sensors. As can be seen from Table 2, the CTD conductivity sensors equipped with the antifouling slow-release material of the present invention exhibited low test errors, with antifouling effects similar to those of imported antifouling materials. In contrast, the CTD conductivity sensors without antifouling treatment exhibited measurement errors that were an order of magnitude greater.

[0059] Table 2 CTD conductivity sensor laboratory retest data

[0060]

[0061] Comparative Example 1

[0062] Other conditions were the same as those in Example 1, except that the step of modifying the montmorillonite with hydrochloric acid was omitted. After testing, the capsaicin loading in the obtained antifouling sustained-release material was 17%.

[0063] Comparative Example 2

[0064] Other conditions were the same as those in Example 1, except that montmorillonite was replaced by halloysite and the hydrochloric acid modification step was omitted. After testing, the capsaicin loading in the obtained antifouling material was 4%.

[0065] According to Comparative Examples 1 and 2, it can be seen that hydrochloric acid modification can significantly increase the loading capacity of montmorillonite for capsaicin, and compared with halloysite, montmorillonite has better loading performance for capsaicin, which is conducive to achieving long-term and slow release of the antifouling agent.

[0066] In summary, the present invention uses hydrochloric acid-modified montmorillonite loaded with capsaicin and other biological antifouling agents to prepare a nanocomposite slow-release material, thereby achieving the effect of slow release of the antifouling agent. The nanocomposite slow-release material is then incorporated into polyethylene to prepare an environmentally friendly antifouling slow-release material that is compatible with the structure of the ocean sensor, thereby achieving slow release of the antifouling agent, protecting the sensor from damage from the surrounding environment for a long time, and extending its service life.

[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An ocean sensor, characterized in that: The ocean sensor includes a CTD conductivity sensor, and the water inlet and outlet of the CTD conductivity sensor are each equipped with a ring-shaped environmentally friendly anti-fouling slow-release material; The preparation method of the environmentally friendly antifouling slow-release material comprises the following steps: Modifying montmorillonite with hydrochloric acid to obtain acid-modified montmorillonite; the hydrochloric acid modification comprises: dispersing the montmorillonite in a hydrochloric acid solution and heating and stirring; the concentration of the hydrochloric acid solution is 1-5 mol / L; the heating and stirring temperature is 70-90° C. and the time is 0.5-24 hours; The acid-modified montmorillonite, water, and an antifouling agent are mixed and liquid-phase intercalated to obtain an antifouling agent-montmorillonite nanocomposite sustained-release material; the antifouling agent is capsaicin; the liquid-phase intercalation specifically comprises: first dispersing the acid-modified montmorillonite in water to form a suspension, placing the suspension in a water bath, stirring and heating to 60-90° C., adding the antifouling agent to the suspension, and stirring at 60-90° C. for 24-32 hours; the mass ratio of the acid-modified montmorillonite to the antifouling agent is 1:1-2; and the amount ratio of the acid-modified montmorillonite to water is 1 g:100-150 mL; The antifouling agent-montmorillonite nanocomposite slow-release material and polyethylene are mixed and compression-molded to obtain the environmentally friendly antifouling slow-release material; the mass ratio of the antifouling agent-montmorillonite nanocomposite slow-release material to the polyethylene is 5-7:24; the compression molding comprises: adding the antifouling agent-montmorillonite nanocomposite slow-release material and the polyethylene to a mold, and sequentially heating and pressurizing the mold containing the mixture; the heating temperature is 160-180° C., the holding time is 0.5-4 hours; the pressurizing pressure is 5-40 MPa, and the holding time is 10-30 seconds.

2. The ocean sensor according to claim 1, characterized in that The polyethylene is high-density polyethylene.

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