A highly flame-retardant and water-resistant material for DC photovoltaic cables and its preparation method

Abstract

The present invention discloses a highly flame-retardant and water-resistant material for direct current photovoltaic cables and a preparation method thereof, relating to the field of cable materials. The present invention obtains a material for direct current photovoltaic cables having both high flame retardancy and water resistance by subjecting a highly flame-retardant component and a water-resistant component to a polyaddition reaction. The polyaddition reaction chemically bonds the highly flame-retardant component and the water-resistant component together through polymerization of carbon-carbon double bonds. The highly flame-retardant component is a phosphorus-containing organic compound containing carbon-carbon double bonds, and the water-resistant component is an acrylate compound. The highly flame-retardant and water-resistant material prepared by the present invention exhibits excellent flame retardancy and water resistance, is halogen-free, and does not require the addition of additional flame retardants, making it environmentally friendly and having broad market value and application prospects.

Description

Technical Field

[0001] The present invention relates to the field of cable materials, in particular to a highly flame-retardant and water-resistant material for direct current photovoltaic cables and a preparation method thereof. Background Art

[0002] As global demand for renewable energy continues to grow, solar energy, as a clean, renewable energy source, has attracted widespread attention. Photovoltaic cables, as the crucial link between solar panels and power systems, have a direct impact on the safety and stability of photovoltaic power generation systems.

[0003] During operation, photovoltaic cables may generate high temperatures due to overloads, short circuits, and other factors, potentially causing fires. Once a cable fire occurs, the fire can spread rapidly, causing serious casualties and property damage. The risk of cable fire is particularly significant in large-scale facilities such as photovoltaic power plants. Therefore, improving the flame retardancy of photovoltaic cable materials is key to ensuring the safe operation of photovoltaic power generation systems. Flame-retardant cable materials maintain structural integrity at high temperatures, preventing the spread of flames and buying valuable time for firefighting and rescue efforts.

[0004] Furthermore, photovoltaic cables inevitably come into contact with moisture during installation and use. This is especially true in outdoor environments, such as rooftops, on the ground, or underwater, where cables are susceptible to corrosion from rain, dew, or groundwater. Furthermore, photovoltaic cables may be exposed to high humidity environments, such as greenhouses or farms. Moisture can accelerate the aging of cable materials, degrade insulation performance, and even cause short circuits. Therefore, improving the water resistance of photovoltaic cable materials is crucial to ensuring long-term, stable operation in harsh environments.

[0005] Chinese patent publication number CN 111961331A discloses a flame-retardant and water-resistant thermoplastic polyurethane elastomer cable material and its preparation method. The material comprises the following components by weight: 60-90 parts TPU resin, 10-40 parts flame retardant, 2-10 parts charring agent, 1-2 parts dispersant, 0.5-1.5 parts molecular chain repair agent, and 0.3-1 part antioxidant. The flame retardant is a surface-modified hypophosphite, obtained by modifying the hypophosphite with a layered double hydroxide or layered silicate. This cable material can be used in applications such as charging pile cables and underwater cables.

[0006] Chinese patent publication number CN 102952357A discloses a water-resistant, flame-retardant PVC cable material for data cables. The raw materials comprise the following components by weight: 100 parts PVC resin, 32-38 parts trioctyl trimellitate, 4-6 parts stabilizer, 8-10 parts flame retardant, and 8-12 parts water-resistant modifier. The water-resistant modifier is formed by coating nano-barium sulfate, calcined kaolin, and nano-silicon dioxide with a silane coupling agent. The water-resistant modifier comprises 2-3 parts by weight of nano-barium sulfate, 4-7.5 parts by weight of calcined kaolin, 2-3 parts by weight of nano-silicon dioxide, and 0.3-0.5 parts by weight of the silane coupling agent. This cable material is adaptable to complex operating environments, offers long-term water resistance, and maintains excellent electrical insulation, mechanical, and flame-retardant properties.

[0007] However, most of the existing flame-retardant and water-resistant photovoltaic cable materials rely on simple mixing and adding flame-retardant components to obtain or enhance flame-retardant properties. In addition, existing flame-retardant and water-resistant photovoltaic cable materials often use halogen-containing components, so there are also many challenges in terms of environmental performance. Summary of the Invention

[0008] The present invention aims to provide a highly flame-retardant and water-resistant material for DC photovoltaic cables and a method for preparing the same. By subjecting a highly flame-retardant component and a water-resistant component to a polyaddition reaction, the highly flame-retardant component and the water-resistant component are chemically bonded together through the polymerization of carbon-carbon double bonds (rather than simply mixed and added). This material, which is both highly flame-retardant and water-resistant, is obtained for use in DC photovoltaic cables, achieving complementary performance between the two materials. The highly flame-retardant and water-resistant material prepared by the present invention exhibits excellent flame retardancy and water resistance, is halogen-free, and requires no additional flame retardants, making it environmentally friendly and promising.

[0009] To achieve the above objectives, this application adopts the following technical solutions:

[0010] In a first aspect, the present application provides a highly flame-retardant and water-resistant material for DC photovoltaic cables. The highly flame-retardant and water-resistant material is obtained by a polyaddition reaction between a highly flame-retardant component and a water-resistant component. The polyaddition reaction chemically bonds the highly flame-retardant and water-resistant components together through the polymerization of carbon-carbon double bonds (rather than simply mixing and adding). The highly flame-retardant component comprises a phosphorus-containing organic compound containing carbon-carbon double bonds, and the water-resistant component comprises an acrylate compound.

[0011] In a second aspect, the present application provides a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable. The method for preparing the highly flame-retardant and water-resistant material comprises:

[0012] An organic solvent, a phosphorus-containing organic compound containing a carbon-carbon double bond, and an acrylate compound are weighed separately and added into a reaction kettle;

[0013] Then, nitrogen gas was introduced for a set time to remove the air from the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0014] Then, the temperature is raised to a first set temperature range, an initiator is added to the reactor, and the mixture is stirred and kept warm under nitrogen protection for a first set reaction time;

[0015] Then, an antioxidant and a UV absorber are added to the reactor, stirred for a second set time, and then the temperature is lowered to a second set temperature range before discharging the material;

[0016] Finally, the obtained material is added to a twin-screw extruder, and extruded and granulated within a third set temperature range to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables.

[0017] Beneficial technical effects:

[0018] This application conducts a polyaddition reaction between a highly flame-retardant component and a water-resistant component, rather than simply mixing and adding them, to develop a highly flame-retardant and water-resistant material for DC photovoltaic cables that can combine the advantages of both components and its preparation method.

[0019] The highly flame-retardant and water-resistant material for DC photovoltaic cables prepared in this application is specifically obtained by a polyaddition reaction of a phosphorus-containing organic compound containing carbon-carbon double bonds and an acrylate compound. This polyaddition reaction chemically bonds the highly flame-retardant component and the water-resistant component together through the polymerization of carbon-carbon double bonds (rather than simply mixing and adding them together), thereby producing a material for DC photovoltaic cables that has both high flame retardancy and water resistance, achieving complementary performance between the two materials.

[0020] In addition, the highly flame-retardant and water-resistant material prepared in the present application has excellent flame retardancy and water resistance, is halogen-free, does not require the addition of additional flame retardants, is very environmentally friendly, and has broad market value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the addition polymerization reaction between the phosphorus-containing organic compound containing carbon-carbon double bonds and the acrylic ester compound.

[0022] Figure 2 This is a schematic structural diagram of the highly flame-retardant and water-resistant material for DC photovoltaic cables prepared in Example 1.

[0023] Figure 3 This is a flow chart for the preparation of highly flame-retardant and water-resistant materials for DC photovoltaic cables. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions, and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below with reference to the following examples. However, this should not be construed as limiting the scope of this application to the following examples. Without departing from the above-mentioned method concepts of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0025] In this application, the terms used in the embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0026] As used in the examples of the present application and the appended claims, the singular forms "or," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] In a first aspect, embodiments of the present application provide a highly flame-retardant and water-resistant material for DC photovoltaic cables. The highly flame-retardant and water-resistant material is obtained by a polyaddition reaction between a highly flame-retardant component and a water-resistant component. The polyaddition reaction chemically bonds the highly flame-retardant and water-resistant components together through the polymerization of carbon-carbon double bonds (rather than simply mixing and adding). The highly flame-retardant component comprises a phosphorus-containing organic compound containing carbon-carbon double bonds, and the water-resistant component comprises an acrylate compound.

[0028] In a possible implementation, the structure of the acrylic acid ester compound is:

[0029]

[0030] Wherein: R represents an organic group, including an alkyl group having a carbon number that is a positive integer and ranges from 12 to 22.

[0031] In one possible implementation, the structure of the phosphorus-containing organic compound containing a carbon-carbon double bond is:

[0032]

[0033] In one possible implementation, the process of the addition polymerization reaction includes:

[0034]

[0035] Wherein: R represents an organic group, including an alkyl group whose carbon number is a positive integer in the range of 12-22; n is a positive integer in the range of 300 to 600.

[0036] Compared with the existing method of directly mixing and adding flame retardant components to photovoltaic cable materials to obtain or enhance flame retardant properties, this application combines phosphorus-containing organic compounds containing carbon-carbon double bonds and acrylic ester compounds through a polyaddition reaction, thereby achieving complementary properties of the two materials.

[0037] In a second aspect, an embodiment of the present application provides a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable. The method for preparing the highly flame-retardant and water-resistant material comprises:

[0038] Weighing an organic solvent, a phosphorus-containing organic compound containing a carbon-carbon double bond, and an acrylate compound respectively, and adding them into a reaction kettle;

[0039] Then, nitrogen gas was introduced for a set time to remove the air from the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0040] Then, the temperature is raised to a first set temperature range, an initiator is added to the reactor, and the mixture is stirred and kept warm under nitrogen protection for a first set reaction time;

[0041] Then, an antioxidant and a UV absorber are added to the reactor, stirred for a second set time, and then cooled to a second set temperature range before discharging;

[0042] Finally, the obtained material is added to a twin-screw extruder, and extruded and granulated within a third set temperature range to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables.

[0043] In one possible implementation, the mass ratio of the organic solvent, the phosphorus-containing organic compound containing a carbon-carbon double bond, the acrylate compound, the initiator, the antioxidant, and the ultraviolet absorber is (30-45): (30-45): (20-35): (2-3): (1-2): (1-2).

[0044] In a possible implementation, the organic solvent includes one or more of ethanol, ether, ethyl acetate, acetone, dichloromethane and toluene.

[0045] In a possible implementation, the initiator includes one or more of an organic peroxide and an azo compound.

[0046] In a possible implementation, the antioxidant includes one or more of a thiobisphenol antioxidant and a secondary amine antioxidant.

[0047] In a possible implementation, the ultraviolet absorber includes one or more of a benzophenone ultraviolet absorber and a benzotriazole ultraviolet absorber.

[0048] In a possible implementation, the set time for introducing nitrogen is 1 to 2 hours.

[0049] In a possible implementation, the first set temperature range is 100-120°C.

[0050] In a possible implementation, the first set reaction time is 4 to 6 hours.

[0051] In a possible implementation, the second set duration is 1 to 2 hours.

[0052] In a possible implementation, the second set temperature range is 50-60°C.

[0053] In a possible implementation, the third set temperature range is 150-160°C.

[0054] The sources of experimental raw materials used in the present invention are as follows:

[0055] Phosphorus-containing organic compounds containing carbon-carbon double bonds: Shanghai MacLean Biochemical Technology Co., Ltd.;

[0056] Acrylate compounds: Jiangsu Bosite Chemical Technology Co., Ltd.

[0057] Solvent: Jiangsu Runfeng Synthetic Technology Co., Ltd.

[0058] Initiator: Jiangsu Runfeng Synthetic Technology Co., Ltd.

[0059] Antioxidant: Jiangsu Bosite Chemical Technology Co., Ltd.

[0060] Ultraviolet absorber: Jiangsu Bosite Chemical Technology Co., Ltd.

[0061] The following will describe in detail a highly flame-retardant and water-resistant material for a DC photovoltaic cable and a preparation method thereof provided in an embodiment of the present application, with reference to different examples.

[0062] Example 1:

[0063] like Figure 3 As shown, a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0064] 1. Weigh ethanol, diphenyl styryl phosphine, and behenyl methacrylate and add them to the reactor;

[0065] 2. Then, nitrogen was introduced for 1 hour to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0066] 3. Then raise the temperature to 110°C, add initiator (dibenzoyl peroxide) into the reactor, and continue stirring and keeping the reaction under nitrogen protection for 5 hours;

[0067] 4. Then add antioxidant (dicetadecyl thiodipropionate) and ultraviolet absorber (2,4-dihydroxybenzophenone) into the reaction kettle, stir for 1.5 hours, then cool to 55°C and discharge;

[0068] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded and granulated at 155° C. to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0069] In the above steps 1 to 5, the mass ratio of the ethanol, diphenyl styryl phosphine, behenyl methacrylate, dibenzoyl peroxide, distearyl thiodipropionate, and 2,4-dihydroxybenzophenone is 35:35:25:2:1.5:1.5.

[0070] The structure of the highly flame-retardant and water-resistant material for DC photovoltaic cables prepared in Example 1 is as follows: Figure 2 shown.

[0071] Example 2:

[0072] like Figure 3 As shown, a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0073] 1. Weigh ether, diphenyl styrylphosphine, and lauryl methacrylate and add them to the reaction kettle;

[0074] 2. Then, nitrogen was introduced for 1.5 hours to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0075] 3. Then, the temperature was raised to 105°C, an initiator (azobisisobutyronitrile) was added to the reactor, and the mixture was stirred and kept warm for 4.5 hours under nitrogen protection.

[0076] 4. Then, add antioxidant (N,N'-di-sec-butyl-p-phenylenediamine) and ultraviolet absorber (2-(2'-hydroxy-5'-methylphenyl)benzotriazole) into the reaction kettle, stir for 1 hour, and then cool to 50°C before discharging;

[0077] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded and granulated at 150° C. to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0078] In the above steps 1 to 5, the mass ratio of the diethyl ether, diphenyl-p-phenylenediamine, lauryl methacrylate, azobisisobutyronitrile, N,N'-di-sec-butyl-p-phenylenediamine, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole is 30:40:25:2:1.5:1.5.

[0079] Example 3:

[0080] like Figure 3 As shown, a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0081] 1. Weigh ethyl acetate, diphenyl 4-phenylphosphine, and octadecyl methacrylate and add them to the reactor;

[0082] 2. Then, nitrogen was introduced for 1 hour to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0083] 3. Then raise the temperature to 120°C, add initiator (dicumyl peroxide) into the reactor, and continue stirring and keeping the reaction under nitrogen protection for 6 hours;

[0084] 4. Then, an antioxidant (didecanyl thiodipropionate) and a UV absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole) were added to the reaction kettle, stirred for 2 hours, and then cooled to 60°C before discharging;

[0085] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded at 160° C., and granulated to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0086] In the above steps 1 to 5, the mass ratio of ethyl acetate, diphenyl styryl phosphine, octadecyl methacrylate, dicumyl peroxide, didodecyl thiodipropionate, and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole is 40:30:25:2:1.5:1.5.

[0087] Example 4:

[0088] like Figure 3 As shown, a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0089] 1. Weigh acetone, diphenyl styryl phosphine, and hexadecyl methacrylate and add them to the reactor;

[0090] 2. Then, nitrogen was introduced for 2 hours to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0091] 3. Then raise the temperature to 115°C, add initiator (di-tert-butyl peroxide) into the reactor, and continue stirring and keeping the reaction under nitrogen protection for 5 hours;

[0092] 4. Then, an antioxidant (ditetradecyl thiodipropionate) and a UV absorber (potassium 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5-sulfonate) were added to the reaction kettle, stirred for 1.2 hours, and then cooled to 58°C before discharging.

[0093] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded and granulated at 158° C. to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0094] In the above steps 1 to 5, the mass ratio of the acetone, diphenyl phenyl phosphine, hexadecyl methacrylate, di-tert-butyl peroxide, ditetradecyl thiodipropionate, and potassium 2,2'-dihydroxy-4,4'-dimethoxybenzophenone-5-sulfonate is 30:35:35:2:1.5:1.5.

[0095] Example 5:

[0096] like Figure 3 As shown, a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0097] 1. Weigh dichloromethane, diphenyl styrylphosphine, and behenyl methacrylate and add them to the reaction kettle;

[0098] 2. Then, nitrogen was introduced for 2 hours to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0099] 3. Then, the temperature was raised to 110°C, an initiator (azobisisobutyronitrile) was added to the reactor, and the mixture was stirred and kept warm for 4.5 hours under nitrogen protection.

[0100] 4. Then, add antioxidant (N,N'-di-sec-octyl-p-phenylenediamine) and ultraviolet absorber (2-(2'-hydroxy-5'-methylphenyl)benzotriazole) into the reaction kettle, stir for 1 hour, and then cool to 55°C before discharging;

[0101] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded and granulated at 155° C. to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0102] In the above steps 1 to 5, the mass ratio of the dichloromethane, diphenyl-p-styrylphosphine, docosyl methacrylate, azobisisobutyronitrile, N,N'-di-sec-octyl-p-phenylenediamine, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole is 35:35:25:3:1:1.

[0103] Example 6:

[0104] like Figure 3 As shown, a method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0105] 1. Weigh toluene, diphenyl styryl phosphine, and lauryl methacrylate and add them to the reactor;

[0106] 2. Then, nitrogen was introduced for 1 hour to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0107] 3. Then raise the temperature to 105°C, add initiator (dibenzoyl peroxide) into the reactor, and continue stirring and keeping the reaction under nitrogen protection for 4.5 hours;

[0108] 4. Then add antioxidant (N,N'-di-sec-butyl-p-phenylenediamine) and UV absorber (2,4-dihydroxybenzophenone) into the reactor, stir for 1.5 hours, then cool to 50°C and discharge;

[0109] 5. Add the material obtained in step 4 to a twin-screw extruder, extrude and granulate at 150° C. to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0110] In the above steps 1 to 5, the mass ratio of toluene, diphenyl-p-styrylphosphine, lauryl methacrylate, dibenzoyl peroxide, N,N'-di-sec-butyl-p-phenylenediamine, and 2,4-dihydroxybenzophenone is 30:35:35:2:1:2.

[0111] Comparative Example 1:

[0112] A method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0113] 1. Weigh toluene and dodecyl methacrylate and add them into the reactor;

[0114] 2. Then, nitrogen was introduced for 1 hour to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0115] 3. Then raise the temperature to 105°C, add initiator (dibenzoyl peroxide) into the reactor, and continue stirring and keeping the reaction under nitrogen protection for 4.5 hours;

[0116] 4. Then add antioxidant (N,N'-di-sec-butyl-p-phenylenediamine) and ultraviolet absorber (2,4-dihydroxybenzophenone) into the reaction kettle, stir for 1.5 hours, then cool to 25°C, add diphenyl-p-phenylenediamine, stir evenly and discharge;

[0117] 5. Finally, the material obtained in step 4 was added to a twin-screw extruder, extruded and granulated at 150°C;

[0118] In the above steps 1 to 5, the mass ratio of toluene, diphenyl-p-styrylphosphine, lauryl methacrylate, dibenzoyl peroxide, N,N'-di-sec-butyl-p-phenylenediamine, and 2,4-dihydroxybenzophenone is 30:35:35:2:1:2.

[0119] Comparative Example 2:

[0120] A method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0121] 1. Weigh ethyl acetate and octadecyl methacrylate and add them into the reactor;

[0122] 2. Then, nitrogen was introduced for 1 hour to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0123] 3. Then raise the temperature to 120°C, add initiator (dicumyl peroxide) into the reactor, and continue stirring and keeping the reaction under nitrogen protection for 6 hours;

[0124] 4. Then, add antioxidant (didecanyl thiodipropionate) and ultraviolet absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole) into the reaction kettle, stir for 2 hours, then cool to 25°C, add diphenyl phenyl phosphine, stir evenly and discharge;

[0125] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded at 160° C., and granulated to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0126] In the above steps 1 to 5, the mass ratio of ethyl acetate, diphenyl styryl phosphine, octadecyl methacrylate, dicumyl peroxide, didodecyl thiodipropionate, and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole is 40:30:25:2:1.5:1.5.

[0127] Comparative Example 3:

[0128] A method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable comprises the following steps:

[0129] 1. Weigh ethanol and behenyl methacrylate and add them into the reactor;

[0130] 2. Then, nitrogen was introduced for 1 hour to remove the air in the reactor, and the mixture was stirred and heated slowly under nitrogen protection;

[0131] 3. Then raise the temperature to 110°C, add initiator (dibenzoyl peroxide) into the reactor, and continue stirring and keeping the reaction under nitrogen protection for 5 hours;

[0132] 4. Then add antioxidant (dicetadecyl thiodipropionate) and ultraviolet absorber (2,4-dihydroxybenzophenone) into the reaction kettle, stir for 1.5 hours, then cool to 25°C, add diphenyl phenyl phosphine, stir evenly and discharge;

[0133] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded and granulated at 155° C. to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables;

[0134] In the above steps 1 to 5, the mass ratio of the ethanol, diphenyl styryl phosphine, behenyl methacrylate, dibenzoyl peroxide, distearyl thiodipropionate, and 2,4-dihydroxybenzophenone is 35:35:25:2:1.5:1.5.

[0135] With reference to GB / T 18380.33-2008, the flame retardant properties of highly flame-retardant and water-resistant materials used in DC photovoltaic cables were tested using the vertical flame spread test of vertically installed bundled wires and cables.

[0136] Refer to GB / T 2951.13-2008 and use electrical test methods to test the water resistance of highly flame-retardant and water-resistant materials used in DC photovoltaic cables.

[0137] Table 1 Performance test results of highly flame-retardant and water-resistant materials used in DC photovoltaic cables

[0138] Flame retardant properties (type) Water resistance (whether it can be penetrated) Example 1 Category A No breakdown Example 2 Category A No breakdown Example 3 Category A No breakdown Example 4 Category A No breakdown Example 5 Category A No breakdown Example 6 Category A No breakdown Comparative Example 1 Category B breakdown Comparative Example 2 Category B breakdown Comparative Example 3 Category B breakdown

[0139] As can be seen from the table, Examples 1-6 exhibit higher flame retardancy and water resistance than Comparative Examples 1-3. This is because in the highly flame-retardant and water-resistant materials for DC photovoltaic cables produced in the Examples of this application, the highly flame-retardant component (a phosphorus-containing organic compound containing carbon-carbon double bonds) and the water-resistant component (an acrylate compound) are chemically bonded together via a polyaddition reaction, achieving complementary performance between the two components. Comparative Examples 1-3, on the other hand, simply mixed and added the flame-retardant component without performing a polyaddition reaction to chemically bond the flame-retardant component and the other components. Consequently, their flame retardancy and water resistance are relatively poor.

[0140] The above results show and describe the basic principles and main features of the present invention as well as the advantages of the present invention.

[0141] Those skilled in the art will appreciate that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the equivalents of the appended claims.

Claims

1. A highly flame-retardant and water-resistant material for DC photovoltaic cables, characterized in that: The highly flame-retardant and water-resistant material is obtained by a polyaddition reaction between a highly flame-retardant component and a water-resistant component; the polyaddition reaction combines the highly flame-retardant component and the water-resistant component in the form of chemical bonds through polymerization of carbon-carbon double bonds; the highly flame-retardant component includes a phosphorus-containing organic compound containing a carbon-carbon double bond; the water-resistant component includes an acrylate compound; the structure of the acrylate compound is: ； Wherein: R represents an organic group, including an alkyl group with a carbon number of positive integers ranging from 12 to 22; The structure of the phosphorus-containing organic compound containing a carbon-carbon double bond is: ； The process of the polyaddition reaction comprises: ； Wherein: R represents an organic group, including an alkyl group whose carbon number is a positive integer ranging from 12 to 22; n is a positive integer ranging from 300 to 600.

2. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 1, characterized in that: The preparation method of the highly flame retardant and water resistant material comprises: Weighing an organic solvent, a phosphorus-containing organic compound containing a carbon-carbon double bond, and an acrylate compound respectively, and adding them into a reaction kettle; Then, nitrogen gas was introduced for a set time to remove the air from the reactor, and the mixture was stirred and heated under nitrogen protection; Then, the temperature is raised to a first set temperature range, an initiator is added to the reactor, and the mixture is stirred and kept warm under nitrogen protection for a first set reaction time; Then, an antioxidant and a UV absorber are added to the reactor, stirred for a second set time, and then cooled to a second set temperature range before discharging; Finally, the obtained material is added to a twin-screw extruder, extruded and granulated within a third set temperature range to obtain a highly flame-retardant and water-resistant material for DC photovoltaic cables; The structure of the phosphorus-containing organic compound containing a carbon-carbon double bond is: ； The structure of the acrylate compound is: ； Wherein: R represents an organic group, including an alkyl group having a positive integer carbon number ranging from 12 to 22.

3. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 2, characterized in that: The mass ratio of the organic solvent, the phosphorus-containing organic compound containing a carbon-carbon double bond, the acrylate compound, the initiator, the antioxidant, and the ultraviolet absorber is (30-45): (30-45): (20-35): (2-3): (1-2): (1-2).

4. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 2, wherein: The organic solvent includes one or more of ethanol, ether, ethyl acetate, acetone, dichloromethane and toluene.

5. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 2, characterized in that: The initiator includes one or more of organic peroxides and azo compounds; the antioxidant includes one or more of thiobisphenol antioxidants and secondary amine antioxidants; and the ultraviolet absorber includes one or more of benzophenone ultraviolet absorbers and benzotriazole ultraviolet absorbers.

6. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 2, characterized in that: The set time for introducing nitrogen is 1 to 2 hours.

7. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 2, characterized in that: The first set temperature range is 100~120℃; the first set reaction time is 4~6 hours; the second set time is 1~2 hours; the second set temperature range is 50~60℃; the third set temperature range is 150~160℃.

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