Flame-retardant insulating material suitable for offshore photovoltaic and preparation method of flame-retardant insulating material

Abstract

The invention relates to the technical field of insulating rubber materials, in particular to a flame-retardant insulating material suitable for offshore photovoltaics and a preparation method of the flame-retardant insulating material. The preparation method comprises the following steps: adding 55-60 parts of high-density polyethylene, 10-25 parts of ethylene propylene diene monomer and 10-15 parts of chloroprene rubber CR121 into an internal mixer at room temperature, plastifying for 1-2 minutes, and then adding the high-density polyethylene, the ethylene propylene diene monomer and the chloroprene rubber CR121 into the internal mixer; adding 30-40 parts of filler, 22-30 parts of a composite flame retardant, 6-10 parts of zinc oxide, 10-20 parts of dioctyl terephthalate, 0.8-3 parts of a vulcanizing agent, 2.5-3.5 parts of an assistant crosslinking agent, 1-2 parts of an antioxidant, 1-2 parts of stearic acid and 0.5-1.5 parts of modified mesoporous carbon spheres, uniformly mixing at 130-150 DEG C, and extruding into a flaky material, so as to obtain the flame-retardant insulating material suitable for offshore photovoltaics. The flame-retardant insulating material suitable for offshore photovoltaic, prepared by the invention, has good flame retardance, mechanical property and salt spray resistance through synergistic cooperation of all the components, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of insulating rubber materials, and particularly relates to a flame-retardant insulating material suitable for offshore photovoltaics and a preparation method thereof. BACKGROUND

[0002] With the exhaustion of fossil energy, countries have shifted their development focus to new renewable energy. In recent years, the research and development of photovoltaic solar systems have made rapid progress. Photovoltaic power stations are used to convert solar energy into electrical energy, and photovoltaic cables are used to transmit the converted electrical energy. Photovoltaic cables, as one of the important components in the photovoltaic industry chain, have a very wide application in the field of photovoltaic power generation. The buffer layer of the cable is mostly composed of rubber. The existing rubber buffer layer can only play a buffering role. In the case of accidental fire, the rubber will decompose into low-molecular combustible substances at high temperatures. Moreover, the salt fog resistance of the existing cable material is also insufficient.

[0003] Therefore, there is an urgent need for a material with good flame-retardant insulation and salt fog resistance to solve the problem of insufficient performance of existing cables. SUMMARY

[0004] The purpose of the present application is to provide a flame-retardant insulating material suitable for offshore photovoltaics and a preparation method thereof, to solve the technical problem of insufficient performance of cables in the prior art.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a flame-retardant insulating material suitable for offshore photovoltaics, which is composed of the following components in parts by weight: high-density polyethylene 55-60 parts, ethylene-propylene-diene rubber 10-25 parts, chloroprene rubber CR121 10-15 parts, filler 30-40 parts, composite flame retardant 22-30 parts, zinc oxide 6-10 parts, dioctyl terephthalate 10-20 parts, vulcanizing agent 0.8-3 parts, cross-linking agent 2.5-3.5 parts, antioxidant 1-2 parts, stearic acid 1-2 parts, and modified mesoporous carbon spheres 0.5-1.5 parts.

[0007] Further, the ethylene-propylene-diene rubber is selected from E-type ethylene-propylene-diene rubber with a third monomer of ethylenic vinyl norbornene, D-type ethylene-propylene-diene rubber with a third monomer of dicyclopentadiene, and / or H-type ethylene-propylene-diene rubber with a third monomer of 1,4-hexadiene.

[0008] Further, the filler is compounded from talc, calcium carbonate, and magnesium oxide in a mass ratio of (5-8):(4-6):(10-12).

[0009] Further, the composite flame retardant is compounded by aluminum hydroxide, modified halloysite and kaolin in a mass ratio of (8-12):(6-9):(1-2).

[0010] Further, the auxiliary crosslinking agent includes ternary ethylene-propylene composite accelerator EG-3 and / or triallyl isocyanurate.

[0011] Further, the vulcanizing agent is sulfur and / or dicumyl peroxide.

[0012] Further, the preparation method of the modified halloysite comprises the following steps:

[0013] The halloysite powder is vacuum dried at 95-105 DEG C for 10-14 h, then methylphenyl diphenyl phosphate is added, ultrasonic dispersion is carried out for 0.3-0.7 h, slow stirring and vacuum extraction are carried out for 0.5-1.5 h, stirring is carried out under normal pressure for 0.3-0.7 h, the above steps are repeated for 2-4 times, centrifugation is carried out, ethanol washing is carried out for 3-5 times, and drying is carried out at 50-70 DEG C for 12-18 h to obtain the modified halloysite; wherein the solid-liquid ratio of the halloysite powder to methylphenyl diphenyl phosphate is (28-56) g:(20-40) mL.

[0014] Further, the preparation method of the antioxidant comprises the following steps:

[0015] N-amino rhodanine, 40wt%-60wt% glutaraldehyde aqueous solution and anhydrous ethanol are added, reflux reaction is carried out for 2-4 h, filtration is carried out, the filter residue is dried at 60-70 DEG C for 6-8 h, the filter residue is added into ethanol for recrystallization, filtration is carried out, and the modified rhodanine is obtained; wherein the mass of N-amino rhodanine, the volume of the glutaraldehyde aqueous solution and the volume of the anhydrous ethanol are in a ratio of (15-30) g:(20-38) mL:(500-1000) mL.

[0016] The modified rhodanine is added into glacial acetic acid, chitosan is added, stirring is carried out at room temperature for 1-3 h, filtration is carried out, the filter residue is washed with NaOH solution for 3-5 times, then washed with water for 3-5 times until the washing liquid is neutral, and finally drying is carried out at room temperature for 20-28 h to obtain the antioxidant; wherein the mass of the modified rhodanine, the volume of the glacial acetic acid and the mass of the chitosan are in a ratio of (24-48) g:(0.25-0.5) L:(48-96) g.

[0017] Further, the preparation method of the modified mesoporous carbon sphere comprises the following steps:

[0018] The sodium polyacrylate is added into a 0.6-0.7 mol / L sucrose solution, and after stirring for 7-9 hours, silica sol and 98 wt% concentrated sulfuric acid are added, and stirring is continued for 25-35 minutes, and then heating is carried out at 100 DEG C for 20-28 hours, and then filtration is carried out, and the filter cake is washed until the pH value is neutral, and then drying is carried out at 95-105 DEG C for 5-7 hours, and then calcination is carried out at 850-950 DEG C for 2-4 hours under a nitrogen atmosphere, and then the silica template is removed by using a NaOH solution under stirring for 12-16 hours, and finally the modified mesoporous carbon spheres are obtained by washing with ethanol and water alternately for 3-5 times; wherein the mass ratio of the sodium polyacrylate, the volume of the sucrose solution, the volume of the silica sol and the volume of the concentrated sulfuric acid is (0.4-0.8) g:(500-1000) mL:(70-140) mL:(12.5-25) mL.

[0019] The mesoporous carbon spheres, anhydrous ethanol, water, bis-[3-(triethoxysilyl)propyl]-tetrasulfide and Tween-20 are mixed, and then constant temperature stirring is carried out at 80-95 DEG C for 20-30 hours, and then centrifugation is carried out, and the obtained precipitate is washed with anhydrous ethanol for 3-5 times, and then drying is carried out at 80-95 DEG C until the constant weight, and then the modified mesoporous carbon spheres are obtained; wherein the mass ratio of the mesoporous carbon spheres, the volume of the anhydrous ethanol, the volume of the water, the mass of the bis-[3-(triethoxysilyl)propyl]-tetrasulfide and the mass of the Tween is (4-6) g:(10-14) mL:(0.9-1.5) mL:(0.4-0.6) g:(0.2-0.3) g.

[0020] In a second aspect of the present application, a preparation method of a flame-retardant insulating material suitable for offshore photovoltaics is provided, comprising the following steps:

[0021] At room temperature, 55-60 parts of high-density polyethylene, 10-25 parts of ethylene-propylene-diene rubber, 10-15 parts of chloroprene rubber CR121 are put into an internal mixer, and after plasticizing for 1-2 minutes, 30-40 parts of fillers, 22-30 parts of composite flame retardants, 6-10 parts of zinc oxide, 10-20 parts of dioctyl terephthalate, 0.8-3 parts of vulcanizing agents, 2.5-3.5 parts of co-crosslinking agents, 1-2 parts of antioxidants, 1-2 parts of stearic acid and 0.5-1.5 parts of modified mesoporous carbon spheres are added, and after uniform mixing at 130-150 DEG C, extrusion is carried out into a sheet material, and then a flame-retardant insulating material suitable for offshore photovoltaics is obtained.

[0022] In summary, due to the adoption of the above technical solutions, the present application has the following beneficial effects:

[0023] 1. In the present application, the sodium polyacrylate dispersant method is used to successfully synthesize mesoporous carbon spheres with high specific surface area and large pore size and uniform size, and then the mesoporous carbon spheres react with silanol functional groups to improve the dispersion effect of the mesoporous carbon spheres in the rubber matrix, and the vulcanizing groups of bis-[3-(triethoxysilane) propyl]-tetrasulfide can react with the double bonds of the rubber molecules, and bis-[3-(triethoxysilane) propyl]-tetrasulfide establishes a "coupling bridge" between the rubber molecules and the mesoporous carbon molecules, and the oxygen on Tween-20 will form a hydrogen bond with the silanol groups on the surface of the mesoporous carbon particles; the fatty chain elements of Tween-20 have good compatibility with the rubber matrix, and at the same time, bis-[3-(triethoxysilane) propyl]-tetrasulfide creates chemical contact between the mesoporous carbon spheres and the rubber matrix, and cooperates to achieve high dispersion and good crosslinking effect of the mesoporous carbon spheres in the rubber matrix; the pores in the modified mesoporous carbon spheres allow the penetration of the ethylene-propylene-diene molecular chain, thereby strengthening the interaction force between the mesoporous carbon spheres and the matrix, while reducing the porosity of the composite material, slowing down the invasion of moisture and salt spray, thereby improving the salt fog resistance of the flame-retardant insulating material, and the higher specific surface area realizes more adsorption of molecular chains on the surface of these carbon spheres, making them better combined with the rubber matrix; and the ethylene-propylene-diene rubber has good reinforcing and toughening effect on high-density polyethylene, which can effectively enhance the comprehensive performance such as tensile strength and impact strength of the flame-retardant insulating material.

[0024] 2. In the present application, the antioxidant is formed by modifying pyrogallol and chitosan through ionic bond complexation, the hydroxyl and amino groups of the chitosan component cooperatively modify the active groups of pyrogallol to capture rubber free radicals and inhibit oxidation reaction; nano-zinc oxide as an ultraviolet shielding agent, cooperates with the antioxidant to enhance the oxidation resistance of the material. At the same time, the polar functional groups of chitosan in the antioxidant reduce the hydrophilicity of the filler, promote its uniform dispersion in the matrix, and thus improve the crosslinking density; the amino groups of chitosan enhance the interfacial adhesion between rubber chains through hydrogen bonding, and cooperate with the modified mesoporous carbon spheres to optimize the mechanical properties of the material.

[0025] 3. In the present application, the organic phosphorus flame retardant methylphenyl diphenyl phosphate has poor thermal stability and is easy to migrate, and the modified halloysite is obtained by loading methylphenyl diphenyl phosphate on halloysite as a carrier. The halloysite channel can effectively inhibit the solubility of methylphenyl diphenyl phosphate in water through hydrogen bonding, capillary force and other forces, thereby improving the water resistance of methylphenyl diphenyl phosphate. Halloysite as an inorganic flame retardant can enhance the thermal stability of rubber, improve the carbon yield of rubber, and reduce the generation of toxic smoke. Halloysite acts on the condensed phase to promote carbonization, and PO and HPO free radicals are generated after thermal decomposition of methylphenyl diphenyl phosphate, which can capture H and OH free radicals in the gas phase. At the same time, it has part of the condensed phase flame retardant effect, which can be in situ superimposed with the condensed phase flame retardant effect of halloysite to form a good synergistic flame retardant effect. At the same time, at high temperature, the mesoporous carbon sphere can absorb and stabilize free radicals and active molecules in the flame, prevent the spread of the flame, and improve the flame retardant effect of the rubber material in cooperation with aluminum hydroxide and kaolin. The flame-retardant insulating material prepared by the present application has good flame retardance and mechanical properties through the synergistic cooperation of each component, and has good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0027] Figure 1 is a mechanical property broken line graph of the flame-retardant insulating material suitable for offshore photovoltaic of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0029] Embodiment 1

[0030] The present embodiment discloses a preparation method of modified halloysite, comprising the following steps:

[0031] The preparation method of the modified halloysite comprises the following steps:

[0032] The 42 g of halloysite powder was vacuum dried at 100℃ for 12 h, then 30 mL of methylphenyl diphenyl phosphate was added, ultrasonic dispersion for 0.5 h, slow stirring and vacuum for 1 h, stirring under normal pressure for 0.5 h, repeated 3 times, centrifuged, washed with ethanol 4 times, and dried at 60℃ for 15 h to obtain the modified halloysite.

[0033] Example 2

[0034] The present embodiment discloses a preparation method of an antioxidant, comprising the following steps:

[0035] (1) 23 g of N-amino rhodanine, 28 mL of 50 wt% glutaraldehyde aqueous solution were added to 0.75 L of anhydrous ethanol, refluxed for 3 h, filtered, and the filter residue was dried at 65℃ for 7 h, then the filter residue was recrystallized in ethanol, filtered to obtain modified rhodanine;

[0036] (2) 36 g of modified rhodanine was added to 0.4 L of glacial acetic acid, then 72 g of chitosan was added, stirred at room temperature for 2 h, filtered, the filter residue was washed with 1 wt% NaOH solution for 4 times, then washed with water for 4 times until the washing liquid was neutral, and finally dried at room temperature for 24 h to obtain the antioxidant.

[0037] Example 3

[0038] The present embodiment discloses a preparation method of modified mesoporous carbon spheres, comprising the following steps:

[0039] (1) 0.6 g of sodium polyacrylate was added to 0.75 L of 0.66 mol / L sucrose solution, stirred for 8 h, then 105 mL of silica sol and 18 mL of 98 wt% concentrated sulfuric acid were added, continued to stir for 30 min, heated at 100℃ for 24 h, filtered, washed the filter cake until the pH value was neutral, dried at 100℃ for 6 h, then calcined at 900℃ for 3 h under nitrogen atmosphere, then removed the silica template with 2 mol / L NaOH solution at room temperature, stirred for 14 h, and finally washed with ethanol and water alternately for 4 times to obtain mesoporous carbon spheres;

[0040] (2) 5 g of mesoporous carbon spheres, 12 mL of anhydrous ethanol, 1.2 mL of water, 0.5 g of bis-[3-(triethoxysilyl)propyl]-tetrasulfide and 0.25 g of Tween-20 were mixed, then constant temperature stirring at 85℃ for 25 h, centrifuged, the obtained precipitate was washed with anhydrous ethanol for 4 times, and dried at 85℃ to constant weight to obtain modified mesoporous carbon spheres.

[0041] Example 4

[0042] A preparation method of a flame-retardant insulating material suitable for offshore photovoltaics, comprising the following steps:

[0043] The mixer was charged with 58 parts of high-density polyethylene, 18 parts of ethylene-propylene-diene rubber, 12 parts of chloroprene rubber CR121 at room temperature, and plasticized for 1.5 min, then 35 parts of filler, 25 parts of composite flame retardant, 8 parts of zinc oxide, 15 parts of dioctyl terephthalate, 2.1 parts of vulcanizing agent, 3 parts of co-crosslinking agent, 1.5 parts of antioxidant prepared in Example 2, 1.5 parts of stearic acid, and 1 part of modified mesoporous carbon spheres prepared in Example 3 were added, and uniformly mixed at 130 DEG C, then extruded into a sheet material to obtain a flame-retardant insulating material suitable for offshore photovoltaics.

[0044] The filler is compounded by talc, calcium carbonate and magnesium oxide with a mass ratio of 6:5:11.5.

[0045] The composite flame retardant is compounded by aluminum hydroxide, modified halloysite prepared in Example 1, and kaolin with a mass ratio of 10:7:1.5.

[0046] The co-crosslinking agent is ethylene-propylene-diene co-promoter EG-3, and the vulcanizing agent is dicumyl peroxide.

[0047] Example 5

[0048] A preparation method of a flame-retardant insulating material suitable for offshore photovoltaics, comprising the following steps:

[0049] The mixer was charged with 58 parts of high-density polyethylene, 18 parts of ethylene-propylene-diene rubber, 12 parts of chloroprene rubber CR121 at room temperature, and plasticized for 1.5 min, then 35 parts of filler, 25 parts of composite flame retardant, 8 parts of zinc oxide, 15 parts of dioctyl terephthalate, 2.1 parts of vulcanizing agent, 3 parts of co-crosslinking agent, 1.5 parts of antioxidant prepared in Example 2, 1.5 parts of stearic acid, and 1 part of modified mesoporous carbon spheres prepared in Example 3 were added, and uniformly mixed at 130 DEG C, then extruded into a sheet material to obtain a flame-retardant insulating material suitable for offshore photovoltaics.

[0050] The filler is compounded by talc, calcium carbonate and magnesium oxide with a mass ratio of 6:5:11.5.

[0051] The composite flame retardant is compounded by aluminum hydroxide, modified halloysite prepared in Example 1, and kaolin with a mass ratio of 10:7:1.5.

[0052] The co-crosslinking agent is ethylene-propylene-diene co-promoter EG-3, and the vulcanizing agent is dicumyl peroxide.

[0053] Example 6

[0054] A preparation method of a flame-retardant insulating material suitable for offshore photovoltaics, comprising the following steps:

[0055] At room temperature, 60 parts of high-density polyethylene, 10 parts of EPDM rubber, and 15 parts of chloroprene rubber CR121 were added to a mixer. After plasticizing for 1 minute, 40 parts of filler, 22 parts of composite flame retardant, 10 parts of zinc oxide, 10 parts of dioctyl terephthalate, 3 parts of vulcanizing agent, 2.5 parts of crosslinking agent, 2 parts of antioxidant prepared in Example 2, 1 part of stearic acid, and 1.5 parts of modified mesoporous carbon spheres prepared in Example 3 were added. After uniform mixing at 130°C, the mixture was extruded into sheets to obtain a flame-retardant insulating material suitable for marine photovoltaic applications.

[0056] The filler is composed of talc, calcium carbonate, and magnesium oxide in a mass ratio of 8:4:11.

[0057] The composite flame retardant is composed of aluminum hydroxide, modified halloysite prepared in Example 1, and kaolin in a mass ratio of 8:9:1.

[0058] The crosslinking agent is a peroxide crosslinking agent, triallyl isocyanurate; the vulcanizing agent is sulfur.

[0059] Example 7

[0060] A method for preparing a flame-retardant insulating material suitable for marine photovoltaic applications includes the following steps:

[0061] At room temperature, 58 parts of high-density polyethylene, 22 parts of ethylene propylene diene monomer (EPDM) rubber, and 11 parts of chloroprene rubber (CR121) were added to a mixer. After plasticizing for 1.5 minutes, 38 parts of filler, 23 parts of composite flame retardant, 9 parts of zinc oxide, 12 parts of dioctyl terephthalate, 2.8 parts of vulcanizing agent, 2.7 parts of crosslinking agent, 2 parts of antioxidant prepared in Example 2, 1 part of stearic acid, and 1.5 parts of modified mesoporous carbon spheres prepared in Example 3 were added. After uniform mixing at 130°C, the mixture was extruded into sheets to obtain a flame-retardant insulating material suitable for marine photovoltaic applications.

[0062] The filler is composed of talc, calcium carbonate and magnesium oxide in a mass ratio of 7:5:11.

[0063] The composite flame retardant is composed of aluminum hydroxide, modified halloysite prepared in Example 1, and kaolin in a mass ratio of 9:8:1.5.

[0064] The crosslinking agent is EG-3, a EPDM composite accelerator; the vulcanizing agent is sulfur.

[0065] Example 8

[0066] A method for preparing a flame-retardant insulating material suitable for marine photovoltaic applications includes the following steps:

[0067] Into the internal mixer at room temperature, 58 parts of high density polyethylene, 12 parts of ethylene propylene diene rubber, 14 parts of chloroprene rubber CR121, first plasticize 1 min, then add 32 parts of filler, 28 parts of composite flame retardant, 7 parts of zinc oxide, 18 parts of dioctyl terephthalate, 1.2 parts of vulcanizing agent, 3 parts of auxiliary crosslinking agent, 1 part of antioxidant prepared in example 2, 2 parts of stearic acid, 0.5 parts of modified mesoporous carbon sphere prepared in example 3, mix uniformly at 140℃, then extrude into sheet material, to obtain a flame-retardant insulating material suitable for offshore photovoltaic.

[0068] The filler is compounded by talcum powder, calcium carbonate and magnesium oxide with a mass ratio of 6:6:10.

[0069] The composite flame retardant is compounded by aluminum hydroxide, modified halloysite prepared in example 1 and kaolin with a mass ratio of 12:6:1.

[0070] The auxiliary crosslinking agent is peroxide auxiliary crosslinking agent triallyl isocyanurate; the vulcanizing agent is dicumyl peroxide.

[0071] Comparative example 1

[0072] Comparative example 1 and example 4, in the process of preparing a flame-retardant insulating material suitable for offshore photovoltaic, the composite flame retardant of comparative example 1 does not add modified halloysite, and other conditions are unchanged.

[0073] Comparative example 2

[0074] Comparative example 2 and example 4, in the process of preparing a flame-retardant insulating material suitable for offshore photovoltaic, the modified mesoporous carbon sphere is not added in comparative example 2, and other conditions are unchanged.

[0075] Experimental example

[0076] The properties of the flame-retardant insulating material suitable for offshore photovoltaic prepared in examples 4-8 and comparative examples 1-2 are tested.

[0077] I. Mechanical properties

[0078] The elongation at break and tear strength are tested according to GB / T528-1998, and the tensile rate is 500mm / min; the test results are shown in table 1:

[0079] Table 1

[0080]

[0081]

[0082] From Figure 1As can be seen from Table 1, the flame-retardant insulation material prepared in Examples 4-8 for offshore photovoltaics has good mechanical properties; as can be seen from the comparison between Comparative Example 1 and Example 4, in the process of preparing the flame-retardant insulation material for offshore photovoltaics, compounding the flame retardant and adding modified halloysite can improve the mechanical properties of the flame-retardant insulation material; as can be seen from the comparison between Comparative Example 2 and Example 4, in the process of preparing the flame-retardant insulation material for offshore photovoltaics, adding modified mesoporous carbon spheres can improve the mechanical properties of the flame-retardant insulation material.

[0083] II. Flame-retardant properties

[0084] The vertical burning test (UL-94) was carried out according to the ISO 9773 standard, and the oxygen index % was tested according to GB / T 2406-1993, and the test results are shown in Table 2:

[0085] Table 2

[0086] Group Limiting oxygen index / % Vertical burning rating Example 4 32.5 V-0 Example 5 31.4 V-0 Example 6 32.1 V-0 Example 7 31.5 V-0 Example 8 30.4 V-1 Comparative Example 1 25.2 V-2 Comparative Example 2 28.9 V-1

[0087] As can be seen from Table 2, the flame-retardant insulation material prepared in Examples 4-8 for offshore photovoltaics has good flame-retardant properties; as can be seen from the comparison between Comparative Example 1 and Example 4, in the process of preparing the flame-retardant insulation material for offshore photovoltaics, compounding the flame retardant and adding modified halloysite can improve the flame-retardant properties of the flame-retardant insulation material; as can be seen from the comparison between Comparative Example 2 and Example 4, in the process of preparing the flame-retardant insulation material for offshore photovoltaics, adding modified mesoporous carbon spheres can improve the flame-retardant properties of the flame-retardant insulation material.

[0088] III. Salt mist resistance

[0089] The flame-retardant insulation materials prepared in Examples 4-8 and Comparative Examples 1-2 were subjected to salt mist resistance detection. The salt mist test temperature was 35℃, the mass fraction of sodium chloride was 5%, the time was 128h, the change rate of elongation at break and the change rate of tear strength were tested, and the data results are shown in Table 3:

[0090] Table 3

[0091] Group Change in elongation at break / % Change in tear strength / % Example 4 0 0 Example 5 1 0 Example 6 1 0 Example 7 0 0 Example 8 1 0 Comparative Example 1 -4 -5 Comparative Example 2 -10 -9

[0092] As can be seen from Table 3, the flame-retardant insulation material suitable for offshore photovoltaics prepared in Examples 4-8 has good salt spray resistance; as can be known from the comparison between Comparative Example 1 and Example 4, in the process of preparing the flame-retardant insulation material suitable for offshore photovoltaics, compounding the flame retardant and adding the modified halloysite can improve the salt spray resistance of the flame-retardant insulation material; as can be known from the comparison between Comparative Example 2 and Example 4, in the process of preparing the flame-retardant insulation material suitable for offshore photovoltaics, adding the modified mesoporous carbon sphere can improve the salt spray resistance of the flame-retardant insulation material.

[0093] The above description is merely preferred embodiments of the present application. The protection scope of the present application is not limited to this, and any modification or change made by those skilled in the art within the technical scope disclosed by the present application and according to the technical scheme and inventive concept of the present application should be covered within the protection scope of the present application.

[0094] The preferred embodiments of the present application disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details and limit the present application to the specific embodiments. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited only by the claims and their full scope and equivalents.

Claims

1. A flame retardant insulation material suitable for offshore photovoltaics, characterized in that, The composition is composed of the following components in weight parts: high-density polyethylene 55-60 parts, ethylene propylene diene rubber 10-25 parts, chloroprene rubber CR121 10-15 parts, filler 30-40 parts, composite flame retardant 22-30 parts, zinc oxide 6-10 parts, dioctyl terephthalate 10-20 parts, vulcanizing agent 0.8-3 parts, auxiliary crosslinking agent 2.5-3.5 parts, antioxidant 1-2 parts, stearic acid 1-2 parts, and modified mesoporous carbon sphere 0.5-1.5 parts.

2. A flame retardant insulation material suitable for offshore photovoltaics according to claim 1, characterized in that, The ethylene propylene diene rubber is selected from E-type ethylene propylene diene rubber with a third monomer of ethylidene norbornene, D-type ethylene propylene diene rubber with a third monomer of dicyclopentadiene, and / or H-type ethylene propylene diene rubber with a third monomer of 1,4-hexadiene.

3. The flame retardant insulation material suitable for offshore photovoltaics according to claim 1, characterized in that, The filler is compounded by talcum powder, calcium carbonate, and magnesium oxide in a mass ratio of (5-8):(4-6):(10-12).

4. The flame retardant insulation material suitable for offshore photovoltaics according to claim 1, characterized in that, The composite flame retardant is compounded by aluminum hydroxide, modified halloysite, and kaolin in a mass ratio of (8-12):(6-9):(1-2).

5. The flame retardant insulation material suitable for offshore photovoltaics according to claim 1, characterized in that, The auxiliary crosslinking agent includes ethylene propylene diene composite accelerator EG-3 and / or triallyl isocyanurate.

6. The flame retardant insulation material suitable for offshore photovoltaics according to claim 1, characterized in that, The vulcanizing agent is sulfur and / or dicumyl peroxide.

7. The flame retardant insulation material suitable for offshore photovoltaics according to claim 4, characterized in that, The preparation method of the modified halloysite comprises the following steps: The halloysite powder is vacuum dried at 95-105℃ for 10-14h, then methylphenyl diphenyl phosphate is added, ultrasonic dispersion is performed for 0.3-0.7h, slow stirring and vacuum extraction are performed for 0.5-1.5h, stirring is performed under normal pressure for 0.3-0.7h, the above steps are repeated for 2-4 times, centrifugation is performed, ethanol washing is performed for 3-5 times, and drying is performed at 50-70℃ for 12-18h to obtain the modified halloysite; wherein the solid-liquid ratio of the halloysite powder to the methylphenyl diphenyl phosphate is (28-56)g:(20-40)mL.

8. The flame retardant insulation material suitable for offshore photovoltaics according to claim 1, characterized in that, The preparation method of the antioxidant comprises the following steps: N-amino rhodanine, 40wt%-60wt% glutaraldehyde aqueous solution, and anhydrous ethanol are added, reflux reaction is performed for 2-4h, filtration is performed, the filter residue is dried at 60-70℃ for 6-8h, the filter residue is added into ethanol for recrystallization, filtration is performed, and the modified rhodanine is obtained; wherein the mass of the N-amino rhodanine, the volume of the glutaraldehyde aqueous solution, and the volume of the anhydrous ethanol are in a ratio of (15-30)g:(20-38)mL:(500-1000)mL; The modified rhodanine is added into glacial acetic acid, chitosan is added, stirring is performed at room temperature for 1-3h, filtration is performed, the filter residue is washed with NaOH solution for 3-5 times, then washed with water for 3-5 times until the washing liquid is neutral, and finally drying is performed at room temperature for 20-28h to obtain the antioxidant; wherein the mass of the modified rhodanine, the volume of the glacial acetic acid, and the mass of the chitosan are in a ratio of (24-48)g:(0.25-0.5)L:(48-96)g.

9. The flame retardant insulation material suitable for offshore photovoltaics according to claim 1, characterized in that, The preparation method of the modified mesoporous carbon sphere comprises the following steps: Sodium polyacrylate is added to a 0.6-0.7 mol / L sucrose solution, stirred for 7-9 h, then silica sol and 98 wt% concentrated sulfuric acid are added, stirring is continued for 25-35 min, heating is carried out at 100°C for 20-28 h, the filter cake is washed to neutral pH, drying is carried out at 95-105°C for 5-7 h, calcination is carried out at 850-950°C for 2-4 h under nitrogen atmosphere, then the silica template is removed with NaOH solution at room temperature, stirring is carried out for 12-16 h, and finally the modified mesoporous carbon spheres are obtained by washing with ethanol and water alternately for 3-5 times; wherein the mass ratio of sodium polyacrylate, the volume of sucrose solution, the volume of silica sol and the volume of concentrated sulfuric acid is (0.4-0.8) g:(500-1000) mL:(70-140) mL:(12.5-25) mL; The mesoporous carbon spheres, anhydrous ethanol, water, bis-[3-(triethoxysilyl)propyl]-tetrasulfide and Tween-20 are mixed, constant temperature stirring is carried out at 80-95°C for 20-30 h, centrifugation is carried out, the obtained precipitate is washed with anhydrous ethanol for 3-5 times, and drying is carried out at 80-95°C until constant weight to obtain modified mesoporous carbon spheres; wherein the mass ratio of mesoporous carbon spheres, the volume of anhydrous ethanol, the volume of water, the mass of bis-[3-(triethoxysilyl)propyl]-tetrasulfide and the mass of Tween is (4-6) g:(10-14) mL:(0.9-1.5) mL:(0.4-0.6) g:(0.2-0.3) g.

10. A process for the preparation of a flame-retardant insulating material suitable for offshore photovoltaics according to any one of claims 1-9, characterized in that, The method comprises the following steps: The high-density polyethylene, the ethylene-propylene-diene rubber, the chloroprene rubber CR121, the filler, the composite flame retardant, the zinc oxide, the dioctyl terephthalate, the vulcanizing agent, the co-crosslinking agent, the antioxidant, the stearic acid and the modified mesoporous carbon spheres are added to the internal mixer at room temperature, plasticizing is carried out for 1-2 min, uniform mixing is carried out at 130-150°C, and then extrusion is carried out to form a sheet-shaped material to obtain the flame-retardant insulating material suitable for offshore photovoltaics.

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