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

Abstract

The application relates to the technical field of high polymer materials, and discloses a high-strength heat-resistant photovoltaic cutting pad and a preparation method thereof. The preparation method comprises the following steps: S1: silane-modified hydrotalcite, methylphenyl dimethoxysilane and dimethyl vinyl ethoxysilane are added into a mixed solvent of toluene and acetone, an aqueous KOH solution is added, reaction is carried out at 55-60 DEG C for 6-8 hours, low-boiling-point products are removed by increasing the temperature, and the silane-modified hydrotalcite is obtained by filtration, washing and drying; and S2: PP resin, the silane-modified hydrotalcite, a compatilizer, a heat-resistant modifier, an antioxidant and an initiator are mixed and granulated in a double-screw extruder, a blank plate is prepared by extrusion and calendering, and the photovoltaic cutting pad is obtained by milling and cutting. The photovoltaic cutting pad comprises the following raw materials in parts by mass: 60-70 parts of PP resin, 10-15 parts of the silane-modified hydrotalcite, 5-10 parts of the heat-resistant modifier and 0.1-0.2 parts of the initiator.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and discloses a high-strength heat-resistant photovoltaic cutting pad and its preparation method. Background Technology

[0002] Silicon rod cutting is a crucial step in the photovoltaic industry. During the cutting process, the cutting pad is an essential auxiliary material, and its quality determines the stability and efficiency of diamond wire cutting. To meet demands, the diameter of the diamond wire used for cutting has gradually decreased, leading to greater vibration during high-speed cutting and increasing instability of the cutting system. Therefore, it is necessary to select a high-strength cutting pad that can resist external forces and reduce vibration to improve the cutting yield.

[0003] Polypropylene is a commonly used thermoplastic with advantages such as good mechanical properties, good chemical corrosion resistance, and almost no water absorption, making it suitable for the preparation of cutting pads. However, its heat resistance needs improvement: during the diamond wire cutting of photovoltaic materials, the intense friction generated continuously releases a large amount of heat. If the cutting pad lacks sufficient heat resistance, it cannot provide stable support for the silicon rod, increasing the risk of breakage. Furthermore, high temperatures accelerate material aging and degradation, shortening the pad's lifespan. Therefore, researching a high-strength, heat-resistant photovoltaic cutting pad and its preparation method is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength, heat-resistant photovoltaic cutting pad and its preparation method, so as to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned 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:

[0006] S1: Silane-modified hydrotalcite, methylphenyldimethoxysilane, and dimethylvinylethoxysilane are mixed in a mixed solvent of toluene and acetone, and KOH aqueous solution is added. The mixture is reacted at 55~60℃ for 6~8h. The low-boiling-point products are removed by heating, and the mixture is filtered, washed, and dried to obtain organosilicon-modified hydrotalcite.

[0007] 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 then milled to obtain a photovoltaic cutting pad.

[0008] In a more optimized manner, the organosilicon-modified hydrotalcite comprises the following raw materials, by mass parts: 30-40 parts silane-modified hydrotalcite, 4-5 parts methylphenyldimethoxysilane, 2-3 parts dimethylvinylethoxysilane, 60-80 parts toluene, 30-50 parts acetone, and 1-2 parts KOH aqueous solution.

[0009] In a more optimized manner, the photovoltaic cutting pad comprises the following raw materials, by weight parts: 60-70 parts PP resin, 10-15 parts organosilicon modified hydrotalcite, 5-8 parts compatibilizer, 5-10 parts heat-resistant modifier, 0.3-0.5 parts antioxidant, and 0.1-0.2 parts initiator.

[0010] Ideally, the initiator is BPO and DCP (dicumyl peroxide) in a mass ratio of 2 to 3:1.

[0011] In a more optimized manner, the preparation of the silane-modified hydrotalcite includes the following steps:

[0012] Step 1: Add 3-aminopropyltriethoxysilane to an aqueous ethanol solution, heat the solution, then add rare earth modified hydrotalcite, keep the solution warm and stir, remove the solvent, and obtain amino modified hydrotalcite.

[0013] Step 2: Add amino-modified hydrotalcite and triethylamine to dehydrated tetrahydrofuran and mix well. Stir under an ice-water bath, slowly add chloromethyltrimethoxysilane, continue the reaction under constant temperature and stirring, remove the solvent by rotary evaporation, and dry to obtain silane-modified hydrotalcite.

[0014] In a more optimized manner, the amino-modified hydrotalcite comprises the following raw materials, in parts by mass: 2-3 parts of 3-aminopropyltriethoxysilane and 20-30 parts of rare earth-modified hydrotalcite;

[0015] The silane-modified hydrotalcite comprises the following raw materials, in parts by mass: 25-30 parts amino-modified hydrotalcite, 1-3 parts triethylamine, and 5-8 parts monochloromethyltrimethoxysilane.

[0016] In a more optimized manner, the preparation of the rare earth modified hydrotalcite includes the following steps: adding magnesium sulfate, aluminum sulfate octadecyl hydrate, cerium nitrate, and yttrium nitrate hexahydrate to water and stirring until homogeneous to obtain solution A; adding sodium hydroxide and sodium carbonate to water and stirring until homogeneous to obtain solution B; adding solution B to solution A under a water bath at 55~60℃ and stirring conditions, reacting for 10~20h, then placing it in a reaction vessel and reacting at 120~130℃ for 5~10h, centrifuging, washing, and drying to obtain rare earth modified hydrotalcite.

[0017] More preferably, solution A comprises the following raw materials in parts by mass: 5-10 parts magnesium sulfate, 10-15 parts aluminum sulfate octadecylhydrate, 0.5-1 part cerium nitrate, 0.3-0.8 parts yttrium hexahydrate, and 50-80 parts water; solution B comprises the following raw materials in parts by mass: 1-3 parts sodium hydroxide, 8-12 parts sodium carbonate, and 50-80 parts water.

[0018] In a more optimized manner, the preparation of the heat-resistant modifier includes the following steps: adding cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stirring at a constant temperature of 0-10°C for 3-5 hours in an ice-water bath, removing the solvent, and obtaining modified cyanuric chloride;

[0019] Modified cyanuric chloride, styrene, methyl acrylate, butyl methacrylate, isobornyl acrylate, maleic anhydride, dodecyl acrylate, and benzoyl peroxide (BPO) were added to a reaction vessel and stirred at 120-130°C for 4-6 hours. Unreacted monomers were removed under vacuum to obtain a heat-resistant modifier.

[0020] In a more optimized manner, the molar ratio of cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine in the modified cyanuric chloride is 1:(1~1.5):(2~2.5):(2.5~3).

[0021] The heat-resistant modifier includes the following raw materials, by mass parts: 5-10 parts modified cyanuric chloride, 10-20 parts styrene, 20-30 parts methyl acrylate, 10-20 parts butyl methacrylate, 2-4 parts isobornyl acrylate, 5-8 parts maleic anhydride, 2-4 parts dodecyl acrylate, and 0.1-0.3 parts benzoyl peroxide.

[0022] Compared with the prior art, the beneficial effects achieved by this invention are as follows: The addition of organosilicon-modified hydrotalcite: The matrix is ​​rare-earth-modified hydrotalcite. Cerium can effectively capture free radicals generated during PP degradation, significantly improving the heat resistance of PP, and can also act as a nucleating agent to improve mechanical properties. Yttrium also increases the thermal decomposition temperature, improving mechanical properties and heat resistance. Rare-earth-modified hydrotalcite is modified with 3-aminopropyltriethoxysilane to give it an amino group on its surface, and then chloromethyltrimethoxysilane is introduced to obtain silane-modified hydrotalcite. This 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, which contains a double bond structure, improves compatibility.

[0023] Adding a heat-resistant modifier: First, diallylamine and 3-aminopropyltriethoxysilane are used to modify cyanuric chloride to obtain modified cyanuric chloride that can participate in the next reaction and has good compatibility with organosilicon-modified hydrotalcite; then, it is copolymerized with styrene, methyl acrylate, butyl methacrylate, isobornyl acrylate, maleic anhydride, and dodecyl acrylate under benzoyl peroxide initiation to obtain the heat-resistant modifier; the monomers selected for polymerization are low polarity monomers with good compatibility with the PP matrix, and maleic anhydride is introduced so that the heat-resistant modifier can also act as a compatibility agent, improving the compatibility between organosilicon-modified hydrotalcite and the PP matrix; the amount of modified cyanuric chloride added needs to be controlled, as excessive addition will lead to an increase in branched structure, affecting compatibility and causing a decrease in performance. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that there are no special restrictions on the suppliers of any of the raw materials involved in this invention. Exemplary examples include: magnesium sulfate (anhydrous magnesium sulfate); cerium nitrate (cerium(III) hexahydrate); chloromethyltrimethoxysilane (CAS: 5926-26-1); KOH aqueous solution (potassium hydroxide aqueous solution (KOH 10%), Zhicheng Biotechnology); 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).

[0026] Unless otherwise specified, all figures below are parts by weight or mass ratios.

[0027] The initiator is BPO and DCP in a mass ratio of 3:1;

[0028] Example 1: S1: Add 8 parts magnesium sulfate, 12 parts aluminum sulfate octadecylhydrate, 0.6 parts cerium nitrate, and 0.5 parts yttrium nitrate hexahydrate to 50 parts water and stir until homogeneous to obtain solution A; add 2 parts sodium hydroxide and 10 parts sodium carbonate to 50 parts water and stir until homogeneous to obtain solution B; add solution B to solution A under stirring conditions in a 60°C water bath and react for 12 hours, then place in a reaction vessel and react at 130°C for 6 hours, centrifuge, wash, and dry to obtain rare earth modified hydrotalcite;

[0029] S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat to 50℃, then add 30 parts of rare earth modified hydrotalcite, keep warm and continue stirring for 5h, remove the solvent, and obtain amino modified hydrotalcite.

[0030] S3: Mix 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine into 60 parts of dehydrated tetrahydrofuran. Stir at 0°C using an ice-water bath. Slowly add 6 parts of monochloromethyltrimethoxysilane at 30 min. Continue stirring at a constant temperature for 2 h. Remove the solvent by rotary evaporation and dry to obtain silane-modified hydrotalcite.

[0031] 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 mixed. 2 parts of KOH aqueous solution were added and reacted at 60°C for 8 hours. The low-boiling-point products were removed by raising the temperature. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite.

[0032] S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, and stir at 0°C for 5 hours in an ice-water bath to remove the solvent, thereby obtaining 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;

[0033] S6: Add 8 parts modified cyanuric chloride, 15 parts styrene, 25 parts methyl acrylate, 15 parts butyl methacrylate, 4 parts isobornyl acrylate, 6 parts maleic anhydride, 3 parts dodecyl acrylate, and 0.1 parts benzoyl peroxide to a reaction vessel, stir and react at 120°C for 6 hours, and remove unreacted monomers under vacuum to obtain a heat-resistant modifier;

[0034] S7: Mix and granulate 60 parts PP resin, 12 parts silicone-modified hydrotalcite, 6 parts compatibilizer, 6 parts heat-resistant modifier, 0.3 parts antioxidant 1010, and 0.1 parts initiator in a twin-screw extruder. Set the temperature of the twin-screw extruder to 220℃. Extrude and calender to prepare a billet. Set the extrusion temperature to 200℃ and control the extrusion speed at 0.5m / min. Mill and shape to obtain a photovoltaic cutting pad.

[0035] Example 2: S1: Add 8 parts magnesium sulfate, 12 parts aluminum sulfate octadecylhydrate, 0.5 parts cerium nitrate, and 0.8 parts yttrium nitrate hexahydrate to 50 parts water and stir until homogeneous to obtain solution A; add 2 parts sodium hydroxide and 10 parts sodium carbonate to 50 parts water and stir until homogeneous to obtain solution B; add solution B to solution A under stirring conditions in a 60°C water bath and react for 12 hours, then place in a reaction vessel and react at 130°C for 6 hours, centrifuge, wash, and dry to obtain rare earth modified hydrotalcite;

[0036] S2: Take 2 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat to 50℃, then add 20 parts of rare earth modified hydrotalcite, keep warm and continue stirring for 5h, remove the solvent, and obtain amino modified hydrotalcite.

[0037] S3: Add 25 parts of amino-modified hydrotalcite and 1 part of triethylamine to 60 parts of dehydrated tetrahydrofuran and mix evenly. Stir at 0°C using an ice-water bath. Slowly add 5 parts of monochloromethyltrimethoxysilane at 30 min and continue stirring at a constant temperature for 1 h. Remove the solvent by rotary evaporation and dry to obtain silane-modified hydrotalcite.

[0038] 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 mixed. 1 part of KOH aqueous solution was added and reacted at 60°C for 6 hours. The low-boiling-point product was removed by heating. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite.

[0039] S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, and stir at 0°C for 5 hours in an ice-water bath to remove the solvent, thereby obtaining 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;

[0040] S6: Add 5 parts modified cyanuric chloride, 10 parts styrene, 20 parts methyl acrylate, 10 parts butyl methacrylate, 2 parts isobornyl acrylate, 5 parts maleic anhydride, 2 parts dodecyl acrylate, and 0.1 parts benzoyl peroxide to a reaction vessel, stir and react at 120°C for 6 hours, and remove unreacted monomers under vacuum to obtain a heat-resistant modifier;

[0041] S7: Mix 60 parts PP resin, 10 parts silicone-modified hydrotalcite, 5 parts compatibilizer, 6 parts heat-resistant modifier, 0.3 parts antioxidant 1010, and 0.1 parts initiator in a twin-screw extruder and granulate them. The temperature of the twin-screw extruder is set at 220℃. Extrusion calendering is used to prepare a billet. The extrusion temperature is set at 200℃ and the extrusion speed is controlled at 0.5m / min. Milling is used to form a photovoltaic cutting pad.

[0042] Comparative Example 1 (using hydrotalcite instead of rare earth modified hydrotalcite, with the remaining methods and steps consistent with Example 1): S1: Add 8 parts magnesium sulfate and 12 parts aluminum sulfate octadecylhydrate to 50 parts water and stir until homogeneous to obtain solution A; add 2 parts sodium hydroxide and 10 parts sodium carbonate to 50 parts water and stir until homogeneous to obtain solution B; add solution B to solution A under stirring conditions in a 60°C water bath and react for 12 hours, then place in a reaction vessel and react at 130°C for 6 hours, centrifuge, wash, and dry to obtain hydrotalcite;

[0043] S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat to 50℃, then add 30 parts of hydrotalcite, keep warm and continue stirring for 5h, remove the solvent, and obtain amino-modified hydrotalcite.

[0044] S3: Mix 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine into 60 parts of dehydrated tetrahydrofuran. Stir at 0°C using an ice-water bath. Slowly add 6 parts of monochloromethyltrimethoxysilane at 30 min. Continue stirring at a constant temperature for 2 h. Remove the solvent by rotary evaporation and dry to obtain silane-modified hydrotalcite.

[0045] 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 mixed. 2 parts of KOH aqueous solution were added and reacted at 60°C for 8 hours. The low-boiling-point products were removed by raising the temperature. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite.

[0046] S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, and stir at 0°C for 5 hours in an ice-water bath to remove the solvent, thereby obtaining 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;

[0047] S6: Add 8 parts modified cyanuric chloride, 15 parts styrene, 25 parts methyl acrylate, 15 parts butyl methacrylate, 4 parts isobornyl acrylate, 6 parts maleic anhydride, 3 parts dodecyl acrylate, and 0.1 parts benzoyl peroxide to a reaction vessel, stir and react at 120°C for 6 hours, and remove unreacted monomers under vacuum to obtain a heat-resistant modifier;

[0048] S7: Mix and granulate 60 parts PP resin, 12 parts silicone-modified hydrotalcite, 6 parts compatibilizer, 6 parts heat-resistant modifier, 0.3 parts antioxidant 1010, and 0.1 parts initiator in a twin-screw extruder. Set the temperature of the twin-screw extruder to 220℃. Extrude and calender to prepare a billet. Set the extrusion temperature to 200℃ and control the extrusion speed at 0.5m / min. Mill and shape to obtain a photovoltaic cutting pad.

[0049] Comparative Example 2 (increasing the amount of modified cyanuric chloride in the heat-resistant modifier, the remaining steps are the same as in Example 1): S1: Add 8 parts magnesium sulfate, 12 parts aluminum sulfate octadecylhydrate, 0.6 parts cerium nitrate, and 0.5 parts yttrium nitrate hexahydrate to 50 parts water and stir evenly to obtain solution A; add 2 parts sodium hydroxide and 10 parts sodium carbonate to 50 parts water and stir evenly to obtain solution B; add solution B to solution A under 60°C water bath and stirring conditions, react for 12 hours, place in a reaction vessel and react at 130°C for 6 hours, centrifuge, wash, and dry to obtain rare earth modified hydrotalcite;

[0050] S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat to 50℃, then add 30 parts of rare earth modified hydrotalcite, keep warm and continue stirring for 5h, remove the solvent, and obtain amino modified hydrotalcite.

[0051] S3: Mix 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine into 60 parts of dehydrated tetrahydrofuran. Stir at 0°C using an ice-water bath. Slowly add 6 parts of monochloromethyltrimethoxysilane at 30 min. Continue stirring at a constant temperature for 2 h. Remove the solvent by rotary evaporation and dry to obtain silane-modified hydrotalcite.

[0052] 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 mixed. 2 parts of KOH aqueous solution were added and reacted at 60°C for 8 hours. The low-boiling-point products were removed by raising the temperature. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite.

[0053] S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, and stir at 0°C for 5 hours in an ice-water bath to remove the solvent, thereby obtaining 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;

[0054] S6: 12 parts modified cyanuric chloride, 15 parts styrene, 25 parts methyl acrylate, 15 parts butyl methacrylate, 4 parts isobornyl acrylate, 6 parts maleic anhydride, 3 parts dodecyl acrylate, and 0.1 parts benzoyl peroxide were added to a reaction vessel and stirred at 120°C for 6 hours. Unreacted monomers were removed under vacuum to obtain a heat-resistant modifier.

[0055] S7: Mix and granulate 60 parts PP resin, 12 parts silicone-modified hydrotalcite, 6 parts compatibilizer, 6 parts heat-resistant modifier, 0.3 parts antioxidant 1010, and 0.1 parts initiator in a twin-screw extruder. Set the temperature of the twin-screw extruder to 220℃. Extrude and calender to prepare a billet. Set the extrusion temperature to 200℃ and control the extrusion speed at 0.5m / min. Mill and shape to obtain a photovoltaic cutting pad.

[0056] Comparative Example 3 (Silane-modified hydrotalcite instead of organosilicon-modified hydrotalcite, with the remaining steps consistent with Example 1): S1: Add 8 parts magnesium sulfate, 12 parts aluminum sulfate octadecylhydrate, 0.6 parts cerium nitrate, and 0.5 parts yttrium nitrate hexahydrate to 50 parts water and stir until homogeneous to obtain solution A; add 2 parts sodium hydroxide and 10 parts sodium carbonate to 50 parts water and stir until homogeneous to obtain solution B; add solution B to solution A under stirring conditions in a 60°C water bath and react for 12 hours, then place in a reaction vessel and react at 130°C for 6 hours, centrifuge, wash, and dry to obtain rare earth-modified hydrotalcite;

[0057] S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat to 50℃, then add 30 parts of rare earth modified hydrotalcite, keep warm and continue stirring for 5h, remove the solvent, and obtain amino modified hydrotalcite.

[0058] S3: Mix 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine into 60 parts of dehydrated tetrahydrofuran. Stir at 0°C using an ice-water bath. Slowly add 6 parts of monochloromethyltrimethoxysilane at 30 min. Continue stirring at a constant temperature for 2 h. Remove the solvent by rotary evaporation and dry to obtain silane-modified hydrotalcite.

[0059] S4: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, and stir at 0°C for 5 hours in an ice-water bath to remove the solvent, thereby obtaining 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;

[0060] S5: Add 8 parts modified cyanuric chloride, 15 parts styrene, 25 parts methyl acrylate, 15 parts butyl methacrylate, 4 parts isobornyl acrylate, 6 parts maleic anhydride, 3 parts dodecyl acrylate, and 0.1 parts benzoyl peroxide to a reaction vessel, stir and react at 120°C for 6 hours, and remove unreacted monomers under vacuum to obtain a heat-resistant modifier.

[0061] S6: Mix and granulate 60 parts PP resin, 12 parts silicone-modified hydrotalcite, 6 parts compatibilizer, 6 parts heat-resistant modifier, 0.3 parts antioxidant 1010, and 0.1 parts initiator in a twin-screw extruder. The temperature of the twin-screw extruder is set at 220℃. Extrusion calendering is used to prepare a billet. The extrusion temperature is set at 200℃, and the extrusion speed is controlled at 0.5m / min. Milling is used to form a photovoltaic cutting pad.

[0062] Comparative Example 4 (the preparation method of the heat-resistant modifier was changed, and the other steps were the same as in Example 1): S1: 8 parts magnesium sulfate, 12 parts aluminum sulfate octadecylhydrate, 0.6 parts cerium nitrate, and 0.5 parts yttrium nitrate hexahydrate were added to 50 parts water and stirred evenly to obtain solution A; 2 parts sodium hydroxide and 10 parts sodium carbonate were added to 50 parts water and stirred evenly to obtain solution B; solution B was added to solution A under stirring conditions in a 60°C water bath and reacted for 12 hours, then placed in a reaction vessel and reacted at 130°C for 6 hours, centrifuged, washed, and dried to obtain rare earth modified hydrotalcite;

[0063] S2: Take 3 parts of 3-aminopropyltriethoxysilane, add it to 100 parts of 50wt% ethanol aqueous solution, heat to 50℃, then add 30 parts of rare earth modified hydrotalcite, keep warm and continue stirring for 5h, remove the solvent, and obtain amino modified hydrotalcite.

[0064] S3: Mix 25 parts of amino-modified hydrotalcite and 2 parts of triethylamine into 60 parts of dehydrated tetrahydrofuran. Stir at 0°C using an ice-water bath. Slowly add 6 parts of monochloromethyltrimethoxysilane at 30 min. Continue stirring at a constant temperature for 2 h. Remove the solvent by rotary evaporation and dry to obtain silane-modified hydrotalcite.

[0065] 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 mixed. 2 parts of KOH aqueous solution were added and reacted at 60°C for 8 hours. The low-boiling-point products were removed by raising the temperature. The mixture was filtered, washed, and dried to obtain organosilicon-modified hydrotalcite.

[0066] S5: Add cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, and stir at 0°C for 5 hours in an ice-water bath to remove the solvent, thereby obtaining 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;

[0067] S6: Add 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 to a reaction vessel, stir and react at 120°C for 6 hours, and remove unreacted monomers under vacuum to obtain a heat-resistant modifier.

[0068] S7: Mix and granulate 60 parts PP resin, 12 parts silicone-modified hydrotalcite, 6 parts compatibilizer, 6 parts heat-resistant modifier, 0.3 parts antioxidant 1010, and 0.1 parts initiator in a twin-screw extruder. Set the temperature of the twin-screw extruder to 220℃. Extrude and calender to prepare a billet. Set the extrusion temperature to 200℃ and control the extrusion speed at 0.5m / min. Mill and shape to obtain a photovoltaic cutting pad.

[0069] Performance testing: Take the photovoltaic cutting pads prepared in Examples 1-2 and Comparative Examples 1-4; (1) Test the thermal shrinkage rate according to ISO23999; (2) Use the photovoltaic cutting pads to slice monocrystalline silicon rods at a cutting speed of 10 cuts / 24 hours and count the breakage rate; see Table 1 for details;

[0070] Table 1:

[0071]

[0072] Conclusions: In Comparative Example 1, replacing rare-earth modified hydrotalcite with hydrotalcite resulted in a significant performance decrease; in Comparative Example 2, increasing the amount of modified cyanuric chloride in the heat-resistant modifier led to changes in the branched structure, affecting compatibility, and therefore the performance was inferior to the examples; in Comparative Example 3, replacing organosilicon modified hydrotalcite with silane modified hydrotalcite resulted in inferior performance compared to the examples; in Comparative Example 4, changing the preparation method of the heat-resistant modifier by adding styrene, methyl acrylate, and butyl methacrylate, while omitting isoborneol acrylate, maleic anhydride, and dodecyl acrylate, the changes in polymer structure and polarity led to changes in compatibility and a performance decrease; in summary, the photovoltaic cutting pad prepared by this invention has the advantages of high strength and heat resistance, stable performance, and low breakage rate when used as a cutting pad.

[0073] 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 foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-strength, heat-resistant photovoltaic cutting pad, characterized in that: Includes the following steps: S1: Silane-modified hydrotalcite, methylphenyldimethoxysilane, and dimethylvinylethoxysilane are mixed in a mixed solvent of toluene and acetone, and KOH aqueous solution is added. The mixture is reacted at 55~60℃ for 6~8h. The low-boiling-point products are removed by heating, and the mixture is filtered, washed, and dried 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 billet, and then milled to obtain a photovoltaic cutting pad. The preparation of the silane-modified hydrotalcite includes the following steps: Step 1: Add 3-aminopropyltriethoxysilane to an aqueous ethanol solution, heat the solution, then add rare earth-modified hydrotalcite, keep the solution warm and stir, remove the solvent, and obtain amino-modified hydrotalcite; Step 2: Add amino-modified hydrotalcite and triethylamine to dehydrated tetrahydrofuran and mix evenly, stir under an ice-water bath, slowly add chloromethyltrimethoxysilane, continue to stir the reaction at a constant temperature, remove the solvent, and dry to obtain silane-modified hydrotalcite; The preparation of the rare earth modified hydrotalcite includes the following steps: magnesium sulfate, aluminum sulfate octadecyl hydrate, cerium nitrate, and yttrium nitrate hexahydrate are added to water and stirred evenly to obtain solution A; sodium hydroxide and sodium carbonate are added to water and stirred evenly to obtain solution B; solution B is added to solution A under water bath and stirring conditions at 55~60℃, and the reaction is carried out for 10~20h; the reaction is carried out in a reaction vessel at 120~130℃ for 5~10h; centrifugation, washing, and drying are performed to obtain rare earth modified hydrotalcite. The preparation of the heat-resistant modifier includes the following steps: adding cyanuric chloride, diallylamine, 3-aminopropyltriethoxysilane, and triethylamine to tetrahydrofuran, stirring at a constant temperature in an ice-water bath for 3-5 hours, removing the solvent to obtain modified cyanuric chloride; adding modified cyanuric chloride, styrene, methyl acrylate, butyl methacrylate, isobornyl acrylate, maleic anhydride, dodecyl acrylate, and benzoyl peroxide to a reaction vessel, stirring and reacting at 120-130°C for 4-6 hours, and removing unreacted monomers under vacuum to obtain the heat-resistant modifier.

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, by mass parts: 30-40 parts silane-modified hydrotalcite, 4-5 parts methylphenyldimethoxysilane, 2-3 parts dimethylvinylethoxysilane, 60-80 parts toluene, 30-50 parts acetone, and 1-2 parts 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 comprises the following raw materials, by weight: 60-70 parts PP resin, 10-15 parts silicone-modified hydrotalcite, 5-8 parts compatibilizer, 5-10 parts heat-resistant modifier, 0.3-0.5 parts antioxidant, and 0.1-0.2 parts initiator.

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

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

6. The method for preparing a high-strength heat-resistant photovoltaic cutting pad according to claim 1, characterized in that: In 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, by mass parts: 5-10 parts modified cyanuric chloride, 10-20 parts styrene, 20-30 parts methyl acrylate, 10-20 parts butyl methacrylate, 2-4 parts isobornyl acrylate, 5-8 parts maleic anhydride, 2-4 parts dodecyl acrylate, and 0.1-0.3 parts benzoyl peroxide.

7. A photovoltaic cutting pad prepared by the method for preparing a high-strength heat-resistant photovoltaic cutting pad according to any one of claims 1 to 6.

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