High-flame-retardant water-resistant material for direct-current photovoltaic cable and preparation method of high-flame-retardant water-resistant material

Abstract

The invention discloses a high-flame-retardant water-resistant material for a direct-current photovoltaic cable and a preparation method of the high-flame-retardant water-resistant material, and relates to the field of cable materials. According to the invention, the high-flame-retardant component and the water-resistant component are subjected to addition polymerization reaction, so that the material for the direct-current photovoltaic cable, which has high flame-retardant property and water resistance, is obtained; in addition polymerization reaction, the high-flame-retardant component and the water-resistant component are combined together in the form of a chemical bond through polymerization of carbon-carbon double bonds; the high-flame-retardant component is a phosphorus-containing organic compound containing a carbon-carbon double bond; and the water-resistant component is an acrylic ester compound. The high-flame-retardancy and water-resistant material prepared by the preparation method disclosed by the invention is very excellent in flame retardancy and water resistance, does not contain halogen, does not need to add an additional flame retardant, is very environment-friendly, and has wide market value and application prospect.

Description

Technical Field

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

[0002] As the global demand for renewable energy continues to grow, solar energy, as a clean and renewable energy source, has received widespread attention. Photovoltaic cables are an important link between solar panels and power systems, and their performance directly affects the safety and stability of photovoltaic power generation systems.

[0003] During operation, photovoltaic cables may generate high temperatures due to overload, short circuit and other reasons, which may cause fires. Once the cable catches fire, the fire will spread rapidly, causing serious casualties and property losses. Especially in large facilities such as photovoltaic power stations, the fire risk of cables cannot be ignored. Therefore, improving the flame retardant properties of photovoltaic cable materials is the key to ensuring the safe operation of photovoltaic power generation systems. Flame retardant cable materials can maintain structural integrity at high temperatures, prevent the spread of flames, and buy precious time for fire fighting and rescue.

[0004] In addition, photovoltaic cables will inevitably come into contact with moisture during the laying and use process. Especially in outdoor environments, such as rooftops, ground or underwater, the cables are easily corroded by rain, dew or groundwater. In addition, photovoltaic cables may also be exposed to environments with high humidity, such as greenhouses or farms. Moisture will accelerate the aging of cable materials, reduce insulation performance, and even cause short circuit accidents. Therefore, improving the water resistance of photovoltaic cable materials is also of great significance to ensure the long-term stable operation of cables in harsh environments.

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

[0006] The Chinese patent with publication number CN 102952357A discloses a water-resistant and flame-retardant PVC cable material for data cables, wherein the raw materials include the following components in parts by weight: 100 parts of PVC resin, 32-38 parts of trioctyl trimellitate, 4-6 parts of stabilizer, 8-10 parts of flame retardant, and 8-12 parts of water-resistant modifier; and the water-resistant modifier is formed by coating nano barium sulfate, calcined kaolin and nano silicon dioxide with a silane coupling agent, wherein the weight of nano barium sulfate in the water-resistant modifier is 2-3 parts, the weight of calcined kaolin is 4-7.5 parts, the weight of nano silicon dioxide is 2-3 parts, and the weight of silane coupling agent is 0.3-0.5 parts. The cable material can adapt to complex use environments, can be water-resistant for a long time, and also maintains excellent electrical insulation properties, mechanical properties 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, and 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 and other aspects. 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 preparation method thereof, by subjecting a highly flame-retardant component and a water-resistant component to addition polymerization, and combining the highly flame-retardant component and the water-resistant component in the form of chemical bonds (rather than simple mixed addition) through the polymerization of carbon-carbon double bonds, thereby obtaining a material for DC photovoltaic cables having both high flame-retardant properties and water-resistant properties, thereby achieving the complementary properties of the two materials. The highly flame-retardant and water-resistant material prepared by the present invention has excellent flame retardancy and water resistance, and does not contain halogen, does not require the addition of additional flame retardants, is very environmentally friendly, and has broad market value and application prospects.

[0009] In order to achieve the above objectives, this application adopts the following technical solutions:

[0010] In the first aspect, the present application provides a highly flame-retardant and water-resistant material for a DC photovoltaic cable. The highly flame-retardant and water-resistant material is obtained by a polyaddition reaction of 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 a chemical bond (rather than a simple mixed addition) through the polymerization of carbon-carbon double bonds; the highly flame-retardant component includes a phosphorus-containing organic compound containing a carbon-carbon double bond; and the water-resistant component includes a class of acrylic ester compounds.

[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] 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;

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

[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 for a first set reaction time under nitrogen protection;

[0015] Then, an antioxidant and an ultraviolet absorber are added to the reaction kettle, 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 into 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 a DC photovoltaic cable.

[0017] Beneficial technical effects:

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

[0019] The highly flame-retardant and water-resistant material for DC photovoltaic cables prepared in the present application is specifically obtained by a polyaddition reaction of a phosphorus-containing organic compound containing a carbon-carbon double bond and an acrylate compound. The polyaddition reaction combines the highly flame-retardant component and the water-resistant component in the form of a chemical bond (rather than a simple mixed addition) through the polymerization of the carbon-carbon double bond, thereby preparing a material for DC photovoltaic cables having both high flame-retardant properties and water-resistant properties, and realizing the complementary properties of 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 It 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 It is a preparation flow chart 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 the present application clearer, the present application is further described in detail below in conjunction with the embodiments. However, this should not be understood as the scope of the present application being limited to the following examples. Without departing from the above-mentioned method ideas of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

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

[0026] As used in the embodiments 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 the first aspect, the embodiment of the present application provides a highly flame-retardant and water-resistant material for a DC photovoltaic cable. The highly flame-retardant and water-resistant material is obtained by a polyaddition reaction of 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 a chemical bond (rather than a simple mixed addition) through the polymerization of carbon-carbon double bonds; the highly flame-retardant component includes a phosphorus-containing organic compound containing a carbon-carbon double bond; and the water-resistant component includes a class of acrylic ester compounds.

[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 positive integer carbon number in the range of 12-22.

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

[0032]

[0033] In a 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 photovoltaic cable material method of directly mixing and adding flame retardant components to obtain or enhance flame retardant properties, the present application combines phosphorus-containing organic compounds containing carbon-carbon double bonds and acrylic ester compounds together through a polyaddition reaction, thereby achieving the 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 is introduced for a set time to remove the air in the reactor, and the reaction mixture is stirred and heated slowly under the protection of nitrogen gas;

[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 for a first set reaction time under nitrogen protection;

[0041] Then, an antioxidant and an ultraviolet absorber are added to the reaction kettle, stirred for a second set time, and then the temperature is lowered to a second set temperature range before discharging the material;

[0042] Finally, the obtained material is added into 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 a DC photovoltaic cable.

[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 time length 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 combine different examples to specifically describe 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.

[0062] Embodiment 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 into the reaction kettle;

[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 the protection of nitrogen;

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

[0067] 4. Then add antioxidant (dioctadecyl 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] Embodiment 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 styryl phosphine and dodecyl methacrylate and add them into a 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 the protection of nitrogen;

[0075] 3. Then raise the temperature to 105°C, add initiator (azobisisobutyronitrile) into the reactor, and continue stirring and keeping 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, then cool to 50°C and discharge;

[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 ether, diphenyl styryl phosphine, dodecyl 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] Embodiment 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 phosphine and octadecyl methacrylate and add them into the reaction kettle;

[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 the protection of nitrogen;

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

[0084] 4. Then, an antioxidant (dilauryl 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 the temperature was lowered to 60°C before discharging;

[0085] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded and granulated at 160° C. 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, diisopropylbenzene peroxide, didodecyl thiodipropionate, and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole is 40:30:25:2:1.5:1.5.

[0087] Embodiment 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 into the reaction kettle;

[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 the protection of nitrogen;

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

[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 the temperature was lowered 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 styryl 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] Embodiment 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 styryl phosphine and dodecyl methacrylate and add them into a 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 the protection of nitrogen;

[0099] 3. Then raise the temperature to 110°C, add initiator (azobisisobutyronitrile) into the reactor, and continue stirring and keeping 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, then cool to 55°C and discharge;

[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 phosphine, dodecyl methacrylate, azobisisobutyronitrile, N,N'-di-sec-octyl-p-phenylenediamine, and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole is 35:35:25:3:1:1.

[0103] Embodiment 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 dodecyl methacrylate and add them into a reaction kettle;

[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 the protection of nitrogen;

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

[0108] 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 50°C and discharge;

[0109] 5. Add the material obtained in step 4 to a twin-screw extruder, extrude and granulate at 150° C., and 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 styryl phosphine, dodecyl 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 the protection of nitrogen;

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

[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 is added to a twin-screw extruder, and extruded and granulated at 150°C;

[0118] In the above steps 1 to 5, the mass ratio of toluene, diphenyl styryl phosphine, dodecyl 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 reaction kettle;

[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 the protection of nitrogen;

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

[0124] 4. Then, an antioxidant (dilauryl thiodipropionate) and a UV absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole) were added to the reaction kettle, and the mixture was stirred for 2 hours. After the mixture was cooled to 25°C, diphenyl phenyl phosphine was added, and the mixture was stirred evenly and then discharged.

[0125] 5. Finally, the material obtained in step 4 is added to a twin-screw extruder, extruded and granulated at 160° C. 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, diisopropylbenzene 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 reaction kettle;

[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 the protection of nitrogen;

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

[0132] 4. Then add an antioxidant (dioctadecyl thiodipropionate) and a UV 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 for DC photovoltaic cables were tested using the vertical flame spread test of vertically installed bundled wires and cables.

[0136] With reference to GB / T 2951.13-2008, the electrical test method was used 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, the flame retardant properties and water resistance of Examples 1-6 are higher than those of Comparative Examples 1-3. This is because in the highly flame retardant and water resistant materials for DC photovoltaic cables prepared in the examples of the present application, the highly flame retardant component (phosphorus-containing organic compound containing carbon-carbon double bonds) and the water resistant component (acrylate compound) are combined together in the form of chemical bonds formed by polyaddition reaction, thus achieving the complementary performance of the two components. Comparative Examples 1-3 simply mix and add the flame retardant component, without performing polyaddition reaction to combine the flame retardant component and other components in the form of chemical bonds, so their flame retardant properties 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 should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of 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 of 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 the 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 a class of acrylic ester compounds.

2. The highly flame retardant and water resistant material for DC photovoltaic cables according to claim 1, characterized in that: The structure of the acrylic acid ester 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 highly flame retardant and water resistant material for DC photovoltaic cables according to claim 1, characterized in that: The structure of the phosphorus-containing organic compound containing a carbon-carbon double bond is:

4. The highly flame retardant and water resistant material for DC photovoltaic cables according to claim 1, characterized in that: The process of the addition polymerization reaction comprises: Wherein: R represents an organic group, including an alkyl group whose carbon number is a positive integer in the range of 12 to 22; n is a positive integer in the range of 300 to 600.

5. A method for preparing a highly flame retardant and water resistant material for a DC photovoltaic cable according to any one of claims 1 to 4, 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 is introduced for a set time to remove the air in the reactor, and the reactor is stirred and heated under the protection of nitrogen gas; 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 for a first set reaction time under nitrogen protection; Then, an antioxidant and an ultraviolet absorber are added to the reaction kettle, stirred for a second set time, and then the temperature is lowered to a second set temperature range before discharging the material; Finally, the obtained material is added into 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 a DC photovoltaic cable.

6. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 5, characterized in that: The mass ratio of the organic solvent, the phosphorus-containing organic compound containing carbon-carbon double bonds, the acrylate compound, the initiator, the antioxidant, and the ultraviolet absorber is (30-45): (30-45): (20-35): (2-3): (1-2): (1-2).

7. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 5, characterized in that: The organic solvent includes one or more of ethanol, ether, ethyl acetate, acetone, dichloromethane and toluene.

8. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 5, 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; the ultraviolet absorber includes one or more of benzophenone ultraviolet absorbers and benzotriazole ultraviolet absorbers.

9. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 5, characterized in that: The set time for introducing nitrogen is 1 to 2 hours.

10. The method for preparing a highly flame-retardant and water-resistant material for a DC photovoltaic cable according to claim 5, characterized in that: The first set temperature range is 100-120°C; 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°C; the third set temperature range is 150-160°C.

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