High-strength heat-resistant photovoltaic cutting base plate and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses a high-strength heat-resistant photovoltaic cutting base plate and a preparation method thereof. The preparation method comprises the following steps: S1, adding silane modified hydrotalcite, methyl phenyl dimethoxysilane and dimethyl vinyl ethyoxyl silane into a mixed solvent of toluene and acetone, mixing, adding a KOH aqueous solution, reacting for 6-8 hours at 55-60 DEG C, heating to remove a low-boiling-point product, filtering, washing and drying to obtain organic silicon modified hydrotalcite; s2, PP resin, organic silicon modified hydrotalcite, a compatilizer, a heat-resistant modifier, an antioxidant and an initiator are mixed and granulated in a twin-screw extruder, a blank plate is prepared through extrusion and calendaring, milling forming is conducted, and the photovoltaic cutting base plate is obtained. The photovoltaic cutting base plate comprises the following raw materials in parts by mass: 60-70 parts of PP resin, 10-15 parts of organic silicon modified hydrotalcite, 5-10 parts of a heat-resistant modifier and 0.1-0.2 part of an initiator.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials and discloses a high-strength heat-resistant photovoltaic cutting pad and a preparation method thereof. Background Art

[0002] Cutting silicon ingots is a crucial step in the photovoltaic industry. During the cutting process, a backing plate is an essential auxiliary material, and its quality determines the stability and efficiency of diamond wire cutting. To meet demand, the diameter of the diamond wire used for cutting has gradually decreased, resulting in large vibration amplitude during high-speed cutting and increasingly unstable cutting systems. Therefore, it is necessary to use a high-strength cutting backing plate that can withstand external forces and reduce vibration to improve cutting yield.

[0003] Polypropylene is a commonly used thermoplastic with advantages such as excellent mechanical properties, good chemical resistance, and virtually no water absorption. It can be used to prepare cutting pads, but its heat resistance needs to be improved. Diamond wire cutting of photovoltaic materials generates intense friction, which continuously releases a large amount of heat. If the cutting pad is not heat-resistant enough, it will not provide stable support for the silicon ingots, increasing the risk of breakage. Furthermore, high temperatures can accelerate material aging and degradation, shortening the pad's service life. Therefore, developing a high-strength, heat-resistant photovoltaic cutting pad and its preparation method is of great significance. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-strength and heat-resistant photovoltaic cutting pad and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a high-strength heat-resistant photovoltaic cutting pad, comprising the following steps: S1: adding silane-modified hydrotalcite, methylphenyldimethoxysilane, and dimethylvinylethoxysilane to a mixed solvent of toluene and acetone, adding a KOH aqueous solution, reacting at 55-60°C for 6-8 hours, raising the temperature to remove low-boiling point products, filtering, washing, and drying to obtain organosilicon-modified hydrotalcite; S2: PP resin, silicone-modified hydrotalcite, compatibilizer, heat-resistant modifier, antioxidant, and initiator are mixed and granulated in a twin-screw extruder, extruded and calendered to prepare a blank, and milled and cut into shape to obtain a photovoltaic cutting pad.

[0006] More optimally, the organosilicon-modified hydrotalcite comprises the following raw materials, calculated by mass: 30-40 parts of silane-modified hydrotalcite, 4-5 parts of methylphenyldimethoxysilane, 2-3 parts of dimethylvinylethoxysilane, 60-80 parts of toluene, 30-50 parts of acetone, and 1-2 parts of KOH aqueous solution.

[0007] More optimally, the photovoltaic cutting pad includes the following raw materials, calculated by mass: 60~70 parts of PP resin, 10~15 parts of silicone modified hydrotalcite, 5~8 parts of compatibilizer, 5~10 parts of heat-resistant modifier, 0.3~0.5 parts of antioxidant, and 0.1~0.2 parts of initiator.

[0008] More optimally, the initiator is BPO and DCP (dicumyl peroxide) in a mass ratio of 2 to 3:1.

[0009] More optimally, the preparation of the silane-modified hydrotalcite comprises the following steps: Step 1: adding 3-aminopropyltriethoxysilane to an ethanol aqueous solution, heating the solution, then adding rare earth modified hydrotalcite, maintaining the temperature while stirring, and removing the solvent to obtain amino modified hydrotalcite; Step 2: Add amino-modified hydrotalcite and triethylamine to dehydrated tetrahydrofuran and mix evenly. Stir in an ice-water bath, slowly add monochloromethyltrimethoxysilane, continue dehydration and stirring at a constant temperature, remove the solvent by rotary evaporation, and dry to obtain silane-modified hydrotalcite.

[0010] More optimally, the amino-modified hydrotalcite comprises the following raw materials, calculated by weight: 2 to 3 parts of 3-aminopropyltriethoxysilane, 20 to 30 parts of rare earth-modified hydrotalcite; The silane-modified hydrotalcite comprises the following raw materials, calculated by mass: 25-30 parts of amino-modified hydrotalcite, 1-3 parts of triethylamine, and 5-8 parts of monochloromethyltrimethoxysilane.

[0011] More optimally, the preparation of the rare earth modified hydrotalcite includes the following steps: adding magnesium sulfate, aluminum sulfate 18-hydrate, cerium nitrate, and yttrium nitrate hexahydrate into water and stirring evenly to obtain liquid A; adding sodium hydroxide and sodium carbonate into water and stirring evenly to obtain liquid B; adding liquid B to liquid A in a water bath at 55-60°C with stirring, reacting for 10-20 hours, placing in a reactor at 120-130°C and reacting for 5-10 hours, centrifuging, washing, and drying to obtain the rare earth modified hydrotalcite.

[0012] More optimally, the liquid A comprises the following raw materials, in parts by mass: 5-10 parts of magnesium sulfate, 10-15 parts of aluminum sulfate 18-hydrate, 0.5-1 parts of cerium nitrate, 0.3-0.8 parts of yttrium nitrate hexahydrate, and 50-80 parts of water; the liquid B comprises the following raw materials, in parts by mass: 1-3 parts of sodium hydroxide, 8-12 parts of sodium carbonate, and 50-80 parts of water.

[0013] More optimally, the preparation of the heat-resistant modifier comprises the following steps: adding cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stirring at a constant temperature of 0-10° C. in an ice-water bath for 3-5 hours, and removing the solvent to obtain modified cyanuric chloride; Add modified cyanuric chloride, styrene, methyl acrylate, butyl methacrylate, isobornyl acrylate, maleic anhydride, dodecyl acrylate, and benzoyl peroxide (BPO) into a reactor, stir and react at 120-130° C. for 4-6 hours, and remove the unreacted monomers in vacuo to obtain a heat-resistant modifier.

[0014] More optimally, in the modified cyanuric chloride, the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine is 1: (1-1.5): (2-2.5): (2.5-3); The heat-resistant modifier includes the following raw materials, calculated by mass: 5-10 parts of modified cyanuric chloride, 10-20 parts of styrene, 20-30 parts of methyl acrylate, 10-20 parts of butyl methacrylate, 2-4 parts of isobornyl acrylate, 5-8 parts of maleic anhydride, 2-4 parts of dodecyl acrylate, and 0.1-0.3 parts of benzoyl peroxide.

[0015] Compared with the prior art, the present invention achieves the following beneficial effects: adding organosilicon-modified hydrotalcite: the matrix is rare earth-modified hydrotalcite; cerium can effectively capture free radicals generated during the degradation of PP, significantly improving the heat stability of PP, and can also serve as a nucleating agent to enhance mechanical properties; yttrium also increases the thermal decomposition temperature, improving mechanical properties and heat resistance; the rare earth-modified hydrotalcite is modified with 3-aminopropyltriethoxysilane to impart amino groups to its surface, and then monochloromethyltrimethoxysilane is introduced to obtain silane-modified hydrotalcite, which is then reacted with methylphenyldimethoxysilane and dimethylvinylethoxysilane to obtain organosilicon-modified hydrotalcite; the introduction of organosilicon can improve heat resistance, hydrophobicity, and flexibility, and the introduction of dimethylvinylethoxysilane results in a double bond structure, thereby improving compatibility; Adding a heat-resistant modifier: First, cyanuric chloride is modified with diallylamine and 3-aminopropyltriethoxysilane to obtain a modified cyanuric chloride that can participate in the next reaction and has good compatibility with the silicone-modified hydrotalcite. Then, it is copolymerized with styrene, methyl acrylate, butyl methacrylate, isobornyl acrylate, maleic anhydride, and dodecyl acrylate under the initiation of benzoyl peroxide to obtain a heat-resistant modifier. The polymerized monomers are selected to have low polarity and good compatibility with the PP matrix. The introduction of maleic anhydride allows the heat-resistant modifier to also act as a compatibilizer, thereby improving the compatibility of the silicone-modified hydrotalcite with the PP matrix. The amount of modified cyanuric chloride added needs to be controlled. Excessive addition will lead to an increase in branched structures, affecting compatibility and resulting in reduced performance. DETAILED DESCRIPTION

[0016] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0017] It should be noted that there are no special restrictions on the purchase manufacturers of all raw materials involved in the present invention, and illustratively include: magnesium sulfate (anhydrous magnesium sulfate); cerium nitrate (cerium (III) nitrate hexahydrate); monochloromethyltrimethoxysilane (CAS: 5926-26-1); KOH aqueous solution (potassium hydroxide aqueous solution (KOH 10%), Zhicheng Biological); methyl acrylate (CAS: 96-33-3); butyl methacrylate (CAS: 97-88-1); isobornyl acrylate (CAS: 5888-33-5); dodecyl acrylate (CAS: 2156-97-0); PP resin (PP7035E4, general type, Dongguan Jinjirui Plastic Raw Materials Co., Ltd.); compatibilizer (maleic anhydride grafted polypropylene PP Moplen EP220R); antioxidant (antioxidant 1010); Unless otherwise specified, the following are parts by mass and mass ratios; The initiator is BPO and DCP in a mass ratio of 3:1; Example 1: S1: 8 parts of magnesium sulfate, 12 parts of aluminum sulfate 18-hydrate, 0.6 parts of cerium nitrate, and 0.5 parts of yttrium nitrate hexahydrate were added to 50 parts of water and stirred uniformly to obtain liquid A; 2 parts of sodium hydroxide and 10 parts of sodium carbonate were added to 50 parts of water and stirred uniformly to obtain liquid B; liquid B was added to liquid A in a 60°C water bath with stirring, and the reaction was carried out for 12 hours. The mixture was placed in a reactor and reacted at 130°C for 6 hours, centrifuged, washed, and dried to obtain rare earth-modified hydrotalcite; S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat it to 50°C, then add 30 parts of rare earth modified hydrotalcite, keep it warm and continue stirring for 5 hours, remove the solvent to obtain amino modified hydrotalcite; S3: 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine were added to 60 parts of dehydrated tetrahydrofuran and mixed evenly. The mixture was stirred at a constant temperature of 0°C in an ice-water bath. 6 parts of monochloromethyltrimethoxysilane were slowly added over 30 minutes. The mixture was stirred at a constant temperature for 2 hours. The solvent was removed by rotary evaporation and dried to obtain silane-modified hydrotalcite. S4: 35 parts of silane-modified hydrotalcite, 4 parts of methylphenyldimethoxysilane, and 3 parts of dimethylvinylethoxysilane were added to 60 parts of toluene and 30 parts of acetone, and 2 parts of KOH aqueous solution were added. The mixture was reacted at 60°C for 8 hours, and the low-boiling point product was removed by heating. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite. S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stir at 0°C in an ice-water bath for 5 hours, and remove the solvent to obtain modified cyanuric chloride; the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine is 1:1:2:3; the amount of tetrahydrofuran added is 8 times the mass of the above substances; S6: 8 parts of modified cyanuric chloride, 15 parts of styrene, 25 parts of methyl acrylate, 15 parts of butyl methacrylate, 4 parts of isobornyl acrylate, 6 parts of maleic anhydride, 3 parts of dodecyl acrylate, and 0.1 part of benzoyl peroxide were added to a reaction kettle, stirred and reacted at 120°C for 6 hours, and unreacted monomers were removed in vacuo to obtain a heat-resistant modifier; S7: 60 parts of PP resin, 12 parts of silicone-modified hydrotalcite, 6 parts of compatibilizer, 6 parts of heat-resistant modifier, 0.3 parts of antioxidant 1010, and 0.1 parts of initiator are mixed and granulated in a twin-screw extruder, and the temperature of the twin-screw extruder is set at 220°C; extrusion and calendering are used to prepare a blank plate, the extrusion temperature is set at 200°C, and the extrusion speed is controlled at 0.5m / min; milling and shaping are performed to obtain a photovoltaic cutting pad.

[0018] Example 2: S1: 8 parts of magnesium sulfate, 12 parts of aluminum sulfate 18-hydrate, 0.5 parts of cerium nitrate, and 0.8 parts of yttrium nitrate hexahydrate were added to 50 parts of water and stirred uniformly to obtain liquid A; 2 parts of sodium hydroxide and 10 parts of sodium carbonate were added to 50 parts of water and stirred uniformly to obtain liquid B; liquid B was added to liquid A in a 60°C water bath with stirring, and the reaction was carried out for 12 hours. The mixture was placed in a reactor and reacted at 130°C for 6 hours, centrifuged, washed, and dried to obtain rare earth-modified hydrotalcite; S2: Take 2 parts of 3-aminopropyltriethoxysilane, add them to 100 parts of 50 wt% ethanol aqueous solution, heat to 50°C, then add 20 parts of rare earth modified hydrotalcite, keep warm and continue stirring for 5 hours, remove the solvent to obtain amino modified hydrotalcite; S3: 25 parts of amino-modified hydrotalcite and 1 part of triethylamine were added to 60 parts of dehydrated tetrahydrofuran and mixed evenly. The mixture was stirred at a constant temperature of 0°C in an ice-water bath. 5 parts of monochloromethyltrimethoxysilane were slowly added over 30 minutes. The mixture was stirred at a constant temperature for 1 hour. The solvent was removed by rotary evaporation and dried to obtain silane-modified hydrotalcite. S4: 30 parts of silane-modified hydrotalcite, 4 parts of methylphenyldimethoxysilane, and 2 parts of dimethylvinylethoxysilane were added to 60 parts of toluene and 30 parts of acetone, and 1 part of KOH aqueous solution was added. The mixture was reacted at 60°C for 6 hours, and the low-boiling point products were removed by heating. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite; S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stir at 0°C in an ice-water bath for 5 hours, and remove the solvent to obtain modified cyanuric chloride; the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine is 1:1:2:3; the amount of tetrahydrofuran added is 8 times the mass of the above substances; S6: Add 5 parts of modified cyanuric chloride, 10 parts of styrene, 20 parts of methyl acrylate, 10 parts of butyl methacrylate, 2 parts of isobornyl acrylate, 5 parts of maleic anhydride, 2 parts of dodecyl acrylate, and 0.1 part of benzoyl peroxide into a reaction kettle, stir and react at 120°C for 6 hours, and remove the unreacted monomers in vacuo to obtain a heat-resistant modifier; S7: 60 parts of PP resin, 10 parts of silicone-modified hydrotalcite, 5 parts of compatibilizer, 6 parts of heat-resistant modifier, 0.3 parts of antioxidant 1010, and 0.1 parts of initiator are mixed and granulated in a twin-screw extruder, and the temperature of the twin-screw extruder is set at 220°C; extrusion and calendering are used to prepare a blank plate, the extrusion temperature is set at 200°C, and the extrusion speed is controlled at 0.5m / min; milling and shaping are performed to obtain a photovoltaic cutting pad.

[0019] Comparative Example 1 (using hydrotalcite instead of rare earth-modified hydrotalcite, the remaining steps are the same as those in Example 1): S1: 8 parts of magnesium sulfate and 12 parts of aluminum sulfate 18-hydrate were added to 50 parts of water and stirred uniformly to obtain Liquid A; 2 parts of sodium hydroxide and 10 parts of sodium carbonate were added to 50 parts of water and stirred uniformly to obtain Liquid B; Liquid B was added to Liquid A in a 60°C water bath with stirring, the reaction was carried out for 12 hours, and the mixture was placed in a reactor at 130°C for 6 hours, centrifuged, washed, and dried to obtain hydrotalcite; S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat it to 50°C, then add 30 parts of hydrotalcite, keep it warm and continue stirring for 5 hours, remove the solvent to obtain amino-modified hydrotalcite; S3: 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine were added to 60 parts of dehydrated tetrahydrofuran and mixed evenly. The mixture was stirred at a constant temperature of 0°C in an ice-water bath. 6 parts of monochloromethyltrimethoxysilane were slowly added over 30 minutes. The mixture was stirred at a constant temperature for 2 hours. The solvent was removed by rotary evaporation and dried to obtain silane-modified hydrotalcite. S4: 35 parts of silane-modified hydrotalcite, 4 parts of methylphenyldimethoxysilane, and 3 parts of dimethylvinylethoxysilane were added to 60 parts of toluene and 30 parts of acetone, and 2 parts of KOH aqueous solution were added. The mixture was reacted at 60°C for 8 hours, and the low-boiling point product was removed by heating. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite. S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stir at 0°C in an ice-water bath for 5 hours, and remove the solvent to obtain modified cyanuric chloride; the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine is 1:1:2:3; the amount of tetrahydrofuran added is 8 times the mass of the above substances; S6: 8 parts of modified cyanuric chloride, 15 parts of styrene, 25 parts of methyl acrylate, 15 parts of butyl methacrylate, 4 parts of isobornyl acrylate, 6 parts of maleic anhydride, 3 parts of dodecyl acrylate, and 0.1 part of benzoyl peroxide were added to a reaction kettle, stirred and reacted at 120°C for 6 hours, and unreacted monomers were removed in vacuo to obtain a heat-resistant modifier; S7: 60 parts of PP resin, 12 parts of silicone-modified hydrotalcite, 6 parts of compatibilizer, 6 parts of heat-resistant modifier, 0.3 parts of antioxidant 1010, and 0.1 parts of initiator are mixed and granulated in a twin-screw extruder, and the temperature of the twin-screw extruder is set at 220°C; extrusion and calendering are used to prepare a blank plate, the extrusion temperature is set at 200°C, and the extrusion speed is controlled at 0.5m / min; milling and shaping are performed to obtain a photovoltaic cutting pad.

[0020] Comparative Example 2 (increasing the amount of modified cyanuric chloride added to the heat-resistant modifier, and the remaining method steps are consistent with Example 1): S1: 8 parts of magnesium sulfate, 12 parts of aluminum sulfate 18-hydrate, 0.6 parts of cerium nitrate, and 0.5 parts of yttrium nitrate hexahydrate are added to 50 parts of water and stirred uniformly to obtain liquid A; 2 parts of sodium hydroxide and 10 parts of sodium carbonate are added to 50 parts of water and stirred uniformly to obtain liquid B; liquid B is added to liquid A in a 60°C water bath with stirring, and the reaction is carried out for 12 hours. The mixture is placed in a reactor and reacted at 130°C for 6 hours, centrifuged, washed, and dried to obtain rare earth-modified hydrotalcite; S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat it to 50°C, then add 30 parts of rare earth modified hydrotalcite, keep it warm and continue stirring for 5 hours, remove the solvent to obtain amino modified hydrotalcite; S3: 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine were added to 60 parts of dehydrated tetrahydrofuran and mixed evenly. The mixture was stirred at a constant temperature of 0°C in an ice-water bath. 6 parts of monochloromethyltrimethoxysilane were slowly added over 30 minutes. The mixture was stirred at a constant temperature for 2 hours. The solvent was removed by rotary evaporation and dried to obtain silane-modified hydrotalcite. S4: 35 parts of silane-modified hydrotalcite, 4 parts of methylphenyldimethoxysilane, and 3 parts of dimethylvinylethoxysilane were added to 60 parts of toluene and 30 parts of acetone, and 2 parts of KOH aqueous solution were added. The mixture was reacted at 60°C for 8 hours, and the low-boiling point product was removed by heating. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite. S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stir at 0°C in an ice-water bath for 5 hours, and remove the solvent to obtain modified cyanuric chloride; the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine is 1:1:2:3; the amount of tetrahydrofuran added is 8 times the mass of the above substances; S6: 12 parts of modified cyanuric chloride, 15 parts of styrene, 25 parts of methyl acrylate, 15 parts of butyl methacrylate, 4 parts of isobornyl acrylate, 6 parts of maleic anhydride, 3 parts of dodecyl acrylate, and 0.1 part of benzoyl peroxide were added to a reaction kettle, stirred and reacted at 120°C for 6 hours, and unreacted monomers were removed in vacuo to obtain a heat-resistant modifier; S7: 60 parts of PP resin, 12 parts of silicone-modified hydrotalcite, 6 parts of compatibilizer, 6 parts of heat-resistant modifier, 0.3 parts of antioxidant 1010, and 0.1 parts of initiator are mixed and granulated in a twin-screw extruder, and the temperature of the twin-screw extruder is set at 220°C; extrusion and calendering are used to prepare a blank plate, the extrusion temperature is set at 200°C, and the extrusion speed is controlled at 0.5m / min; milling and shaping are performed to obtain a photovoltaic cutting pad.

[0021] Comparative Example 3 (silane-modified hydrotalcite was used instead of silicone-modified hydrotalcite; the remaining steps were the same as in Example 1): S1: 8 parts of magnesium sulfate, 12 parts of aluminum sulfate 18-hydrate, 0.6 parts of cerium nitrate, and 0.5 parts of yttrium nitrate hexahydrate were added to 50 parts of water and stirred uniformly to obtain Solution A; 2 parts of sodium hydroxide and 10 parts of sodium carbonate were added to 50 parts of water and stirred uniformly to obtain Solution B; Solution B was added to Solution A in a 60°C water bath with stirring, and the reaction was carried out for 12 hours. The mixture was then placed in a reactor at 130°C and reacted for 6 hours. The mixture was centrifuged, washed, and dried to obtain a rare earth-modified hydrotalcite. S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat it to 50°C, then add 30 parts of rare earth modified hydrotalcite, keep it warm and continue stirring for 5 hours, remove the solvent to obtain amino modified hydrotalcite; S3: 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine were added to 60 parts of dehydrated tetrahydrofuran and mixed evenly. The mixture was stirred at a constant temperature of 0°C in an ice-water bath. 6 parts of monochloromethyltrimethoxysilane were slowly added over 30 minutes. The mixture was stirred at a constant temperature for 2 hours. The solvent was removed by rotary evaporation and dried to obtain silane-modified hydrotalcite. S4: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stir at 0°C in an ice-water bath for 5 hours, and remove the solvent to obtain modified cyanuric chloride; the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine is 1:1:2:3; the amount of tetrahydrofuran added is 8 times the mass of the above substances; S5: Add 8 parts of modified cyanuric chloride, 15 parts of styrene, 25 parts of methyl acrylate, 15 parts of butyl methacrylate, 4 parts of isobornyl acrylate, 6 parts of maleic anhydride, 3 parts of dodecyl acrylate, and 0.1 part of benzoyl peroxide into a reaction kettle, stir and react at 120°C for 6 hours, and remove the unreacted monomers in vacuo to obtain a heat-resistant modifier; S6: 60 parts of PP resin, 12 parts of silicone-modified hydrotalcite, 6 parts of compatibilizer, 6 parts of heat-resistant modifier, 0.3 parts of antioxidant 1010, and 0.1 parts of initiator are mixed and granulated in a twin-screw extruder, and the temperature of the twin-screw extruder is set at 220°C; extrusion and calendering are used to prepare a blank plate, the extrusion temperature is set at 200°C, and the extrusion speed is controlled at 0.5m / min; milling and shaping are performed to obtain a photovoltaic cutting pad.

[0022] Comparative Example 4 (the preparation method of the heat-resistant modifier was changed, and the remaining steps were the same as those in Example 1): S1: 8 parts of magnesium sulfate, 12 parts of aluminum sulfate 18-hydrate, 0.6 parts of cerium nitrate, and 0.5 parts of yttrium nitrate hexahydrate were added to 50 parts of water and stirred uniformly to obtain liquid A; 2 parts of sodium hydroxide and 10 parts of sodium carbonate were added to 50 parts of water and stirred uniformly to obtain liquid B; liquid B was added to liquid A in a 60°C water bath with stirring, and the reaction was carried out for 12 hours. The mixture was then placed in a reactor and reacted at 130°C for 6 hours, centrifuged, washed, and dried to obtain rare earth-modified hydrotalcite; S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat it to 50°C, then add 30 parts of rare earth modified hydrotalcite, keep it warm and continue stirring for 5 hours, remove the solvent to obtain amino modified hydrotalcite; S3: 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine were added to 60 parts of dehydrated tetrahydrofuran and mixed evenly. The mixture was stirred at a constant temperature of 0°C in an ice-water bath. 6 parts of monochloromethyltrimethoxysilane were slowly added over 30 minutes. The mixture was stirred at a constant temperature for 2 hours. The solvent was removed by rotary evaporation and dried to obtain silane-modified hydrotalcite. S4: 35 parts of silane-modified hydrotalcite, 4 parts of methylphenyldimethoxysilane, and 3 parts of dimethylvinylethoxysilane were added to 60 parts of toluene and 30 parts of acetone, and 2 parts of KOH aqueous solution were added. The mixture was reacted at 60°C for 8 hours, and the low-boiling point product was removed by heating. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite. S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stir at 0°C in an ice-water bath for 5 hours, and remove the solvent to obtain modified cyanuric chloride; the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine is 1:1:2:3; the amount of tetrahydrofuran added is 8 times the mass of the above substances; S6: 8 parts of modified cyanuric chloride, 20 parts of styrene, 35 parts of methyl acrylate, 15 parts of butyl methacrylate, and 0.1 parts of benzoyl peroxide were added to a reaction kettle, stirred and reacted at 120°C for 6 hours, and unreacted monomers were removed in vacuo to obtain a heat-resistant modifier; S7: 60 parts of PP resin, 12 parts of silicone-modified hydrotalcite, 6 parts of compatibilizer, 6 parts of heat-resistant modifier, 0.3 parts of antioxidant 1010, and 0.1 parts of initiator are mixed and granulated in a twin-screw extruder, and the temperature of the twin-screw extruder is set at 220°C; extrusion and calendering are used to prepare a blank plate, the extrusion temperature is set at 200°C, and the extrusion speed is controlled at 0.5m / min; milling and shaping are performed to obtain a photovoltaic cutting pad.

[0023] Performance test: Take the photovoltaic cutting pads prepared in Examples 1-2 and Comparative Examples 1-4; (1) refer to ISO23999 and test the thermal shrinkage change rate; (2) Use the photovoltaic cutting pads to slice single crystal silicon rods at a cutting speed of 10 cuts / 24 hours, and calculate the wire breakage rate; see Table 1 for details; Table 1:

[0024] Conclusion: Comparative Example 1 replaces rare earth modified hydrotalcite with hydrotalcite, and the performance decreases significantly; Comparative Example 2 increases the amount of modified cyanuric chloride added in the heat-resistant modifier, which will lead to changes in the branched structure and affect the compatibility, so the performance is not as good as the embodiment; Comparative Example 3 replaces silicone modified hydrotalcite with silane-modified hydrotalcite, and the performance is not as good as the embodiment; Comparative Example 4 changes the preparation method of the heat-resistant modifier, adds styrene, methyl acrylate, and butyl methacrylate, and does not contain isobornyl acrylate, maleic anhydride, and dodecyl acrylate. Due to the changes in polymer structure and polarity, the compatibility changes and the performance decreases; In summary, the photovoltaic cutting pad prepared by the present invention has the advantages of high strength and heat resistance, stable performance when used as a cutting pad, and low wire breakage rate.

[0025] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high-strength, heat-resistant photovoltaic cutting pad, characterized by: The following steps are involved: S1: adding silane-modified hydrotalcite, methylphenyldimethoxysilane, and dimethylvinylethoxysilane to a mixed solvent of toluene and acetone, adding a KOH aqueous solution, reacting at 55-60°C for 6-8 hours, raising the temperature to remove low-boiling point products, filtering, washing, and drying to obtain organosilicon-modified hydrotalcite; S2: PP resin, silicone-modified hydrotalcite, compatibilizer, heat-resistant modifier, antioxidant, and initiator are mixed and granulated in a twin-screw extruder, extruded and calendered to prepare a blank, and milled and cut into shape to obtain a photovoltaic cutting pad.

2. The method for preparing a high-strength heat-resistant photovoltaic cutting pad according to claim 1, characterized in that: The organosilicon-modified hydrotalcite comprises the following raw materials, calculated by mass: 30-40 parts of silane-modified hydrotalcite, 4-5 parts of methylphenyldimethoxysilane, 2-3 parts of dimethylvinylethoxysilane, 60-80 parts of toluene, 30-50 parts of acetone, and 1-2 parts of KOH aqueous solution.

3. The method for preparing a high-strength heat-resistant photovoltaic cutting pad according to claim 1, characterized in that: The photovoltaic cutting pad includes the following raw materials, calculated by mass: 60-70 parts of PP resin, 10-15 parts of silicone-modified hydrotalcite, 5-8 parts of compatibilizer, 5-10 parts of heat-resistant modifier, 0.3-0.5 parts of antioxidant, and 0.1-0.2 parts of initiator.

4. The method for preparing a high-strength heat-resistant photovoltaic cutting pad according to claim 1, characterized in that: The preparation of the silane-modified hydrotalcite comprises the following steps: Step 1: adding 3-aminopropyltriethoxysilane to an ethanol aqueous solution, heating the solution, then adding rare earth modified hydrotalcite, maintaining the temperature while stirring, and removing the solvent to obtain amino modified hydrotalcite; Step 2: Add amino-modified hydrotalcite and triethylamine to dehydrated tetrahydrofuran and mix evenly. Stir in an ice-water bath, slowly add monochloromethyltrimethoxysilane, continue stirring at a constant temperature to react, remove the solvent, and dry to obtain silane-modified hydrotalcite.

5. The method for preparing a high-strength heat-resistant photovoltaic cutting pad according to claim 4, characterized in that: The amino-modified hydrotalcite comprises the following raw materials, calculated by weight: 2 to 3 parts of 3-aminopropyltriethoxysilane and 20 to 30 parts of rare earth-modified hydrotalcite; The silane-modified hydrotalcite comprises the following raw materials, calculated by mass: 25-30 parts of amino-modified hydrotalcite, 1-3 parts of triethylamine, and 5-8 parts of monochloromethyltrimethoxysilane.

6. The method for preparing a high-strength heat-resistant photovoltaic cutting pad according to claim 1, characterized in that: The preparation of the rare earth modified hydrotalcite comprises the following steps: adding magnesium sulfate, aluminum sulfate 18-hydrate, cerium nitrate, and yttrium nitrate hexahydrate into water and stirring uniformly to obtain liquid A; adding sodium hydroxide and sodium carbonate into water and stirring uniformly to obtain liquid B; adding liquid B into liquid A in a water bath at 55-60° C. with stirring, reacting for 10-20 hours, placing the mixture in a reactor at 120-130° C. and reacting for 5-10 hours, centrifuging, washing, and drying to obtain the rare earth modified hydrotalcite.

7. The method for preparing a high-strength and heat-resistant photovoltaic cutting pad according to claim 6, characterized in that: The liquid A comprises the following raw materials, in parts by mass: 5-10 parts of magnesium sulfate, 10-15 parts of aluminum sulfate 18-hydrate, 0.5-1 parts of cerium nitrate, 0.3-0.8 parts of yttrium nitrate hexahydrate, and 50-80 parts of water; the liquid B comprises the following raw materials, in parts by mass: 1-3 parts of sodium hydroxide, 8-12 parts of sodium carbonate, and 50-80 parts of water.

8. The method for preparing a high-strength heat-resistant photovoltaic cutting pad according to claim 1, characterized in that: The preparation of the heat-resistant modifier comprises the following steps: adding cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane and triethylamine to tetrahydrofuran, stirring at a constant temperature for 3 to 5 hours in an ice-water bath, and removing the solvent to obtain modified cyanuric chloride; Add modified cyanuric chloride, styrene, methyl acrylate, butyl methacrylate, isobornyl acrylate, maleic anhydride, dodecyl acrylate, and benzoyl peroxide into a reaction kettle, stir and react at 120-130° C. for 4-6 hours, and remove unreacted monomers in vacuo to obtain a heat-resistant modifier.

9. The method for preparing a high-strength and heat-resistant photovoltaic cutting pad according to claim 8, characterized in that: In the modified cyanuric chloride, the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane and triethylamine is 1: (1-1.5): (2-2.5): (2.5-3); The heat-resistant modifier includes the following raw materials, calculated by mass: 5-10 parts of modified cyanuric chloride, 10-20 parts of styrene, 20-30 parts of methyl acrylate, 10-20 parts of butyl methacrylate, 2-4 parts of isobornyl acrylate, 5-8 parts of maleic anhydride, 2-4 parts of dodecyl acrylate, and 0.1-0.3 parts of benzoyl peroxide.

10. A photovoltaic cutting pad prepared according to the method for preparing a high-strength and heat-resistant photovoltaic cutting pad according to any one of claims 1 to 9.

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