Preparation method of flame-retardant anti-ultraviolet PP plate

Abstract

The invention discloses a preparation method of a flame-retardant anti-ultraviolet PP (polypropylene) board, and the PP board comprises the following raw materials in parts by weight: 80-100 parts of PP master batch, 8-10 parts of a modified additive, 5-10 parts of silicon dioxide, 3-5 parts of zinc borate and 3-5 parts of zirconium oxide. Molecules of the modified additive can convert harmful ultraviolet light energy into harmless heat energy and release the heat energy, silicon dioxide has high reflection and scattering capacity and can reduce ultraviolet rays penetrating through the surface layer of the material, and meanwhile hydroxyl on the surface of silicon dioxide can capture free radicals excited by the ultraviolet rays, so that the photooxidation chain reaction is interrupted, and the photooxidation effect is improved. The anti-ultraviolet effect of the material can be improved through cooperation with the modified additive, the modified additive can release amino, carbon dioxide and water vapor during combustion, then a porous silicon-carbon layer is formed on the surface of the material, the structure of the silicon-carbon layer can be strengthened through addition of zirconium oxide and zinc borate, then oxygen is isolated, and the flame-retardant effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of PP plate preparation, and in particular to a method for preparing a flame-retardant and UV-resistant PP plate. Background Art

[0002] Polypropylene is one of the five most common plastics in the world today. It is an important member of polymer materials and the first synthetic isotactic polymer to achieve industrial mass production. Polypropylene resin has abundant raw materials, low production cost, and light weight. It is a thermoplastic resin that is easy to mold and process and has excellent physical and mechanical properties. It has a wide range of applications, covering thermoplastics, fibers, films and other fields. Soon after isotactic polypropylene was industrialized, polypropylene was industrialized, but polypropylene has an obvious disadvantage that it will turn yellow and become brittle after long-term outdoor use, and when affected by open flames, it will burn quickly and produce a lot of dripping, which may cause secondary combustion. Therefore, in order to increase the service life and enhance the safety of use, polypropylene needs to be modified to be UV-resistant and flame-retardant. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a flame-retardant and UV-resistant PP sheet, which solves the problem that the current PP sheet has poor flame-retardant effect and turns yellow and brittle after long-term use.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A method for preparing a flame-retardant and UV-resistant PP sheet comprises the following steps: Weigh the following raw materials in parts by weight: 80-100 parts of PP masterbatch, 8-10 parts of modifying additives, 5-10 parts of silicon dioxide, 3-5 parts of zinc borate and 3-5 parts of zirconium oxide, mix the raw materials and add them into an extruder, and extrude and press them under the conditions of zone 1 temperature of 160-165°C, zone 2 temperature of 165-175°C, zone 3 temperature of 175-185°C, zone 4 temperature of 185-195°C and die head temperature of 180-185°C to obtain a flame retardant and UV-resistant PP sheet.

[0005] Further, the modified additive is prepared by the following steps: Step A1: Concentrated hydrochloric acid and deionized water are mixed, and dinitrobenzidine is added under the conditions of a rotation speed of 600-800 r / min and a temperature of 20-25° C., and the mixture is reacted for 30-40 min, and then the temperature is lowered to 0-5° C., sodium nitrite is added, and the mixture is reacted for 30-40 min to obtain a diazonium salt, and resorcinol, sodium carbonate and deionized water are mixed uniformly, and diazonium salt is added under the conditions of a rotation speed of 600-800 r / min and a temperature of 0-5° C., and the mixture is reacted for 2-3 h to obtain an azo compound; Step A2: uniformly mix the azo compound, sodium hydroxide and deionized water, stir and add thiourea dioxide at a speed of 60-80 r / min and a temperature of 70-75° C., heat to 80-85° C., react for 3-4 hours, add glacial acetic acid, filter and remove the filtrate to obtain intermediate 1, mix intermediate 1, potassium carbonate and DMF, stir for 1-1.5 hours at a speed of 200-300 r / min and a temperature of 80-85° C., add di(4-nitrophenyl)phosphinoyl chloride, and continue to react for 5-7 hours to obtain intermediate 2; Step A3: Intermediate 2, palladium carbon catalyst and tetrahydrofuran are mixed evenly, hydrogen is introduced to a standard atmospheric pressure, and the reaction is carried out at a speed of 120-150r / min and a temperature of 40-50°C for 6-8h to obtain intermediate 3. Intermediate 3, modified monomer, urea and DMF are mixed, and the reaction is carried out at a speed of 150-200r / min and a temperature of 60-65°C for 5-6h to obtain a modified additive.

[0006] Furthermore, the amount ratio of concentrated hydrochloric acid, deionized water, dinitrobenzidine and sodium nitrite in step A1 is 25mL:20mL:5g:5.5g, the mass fraction of concentrated hydrochloric acid is 36%, and the amount ratio of resorcinol, sodium carbonate, deionized water and diazonium salt is 120mmol:8.5g:200mL:60mmol.

[0007] Furthermore, the amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step A2 is 5 g:10 g:75 mL:1 g:25 mL, and the molar ratio of intermediate 1, potassium carbonate and di(4-nitrophenyl)phosphoryl chloride is 1:2.1:2.

[0008] Furthermore, the usage ratio of the intermediate 2, palladium carbon catalyst and tetrahydrofuran described in step A3 is 1 mmol:0.1 g:10 mL, and the molar ratio of the intermediate 3, the modified monomer and urea is 1:5:4.

[0009] Further, the modified monomer is prepared by the following steps: Step B1: octamethylcyclotetrasiloxane, tetramethyldisiloxane, tetramethylammonium hydroxide and dimethyl sulfoxide are mixed, nitrogen is introduced for protection, and the reaction is carried out for 10-12 hours at a speed of 120-150 r / min and a temperature of 90-95° C. to obtain a dihydrogen-terminated polysiloxane; the dihydrogen-terminated polysiloxane, acrylic acid, chloroplatinic acid and DMF are mixed uniformly, nitrogen is introduced for protection, and the reaction is carried out for 6-8 hours at a speed of 150-200 r / min and a temperature of 80-85° C. to obtain a carboxylated polysiloxane; Step B2: Carboxylated polysiloxane, ethylene glycol amine, dicyclohexylcarbodiimide and toluene are mixed, and the mixture is reacted for 3-5 hours at a rotation speed of 300-500 r / min and a temperature of 30-35°C to obtain a modified polysiloxane. The modified polysiloxane, phosphorus oxychloride and DMF are evenly mixed, and the mixture is stirred at a rotation speed of 200-300 r / min and a temperature of 0-3°C, and pyridine is added, and the mixture is heated to 25-30°C and reacted for 3-4 hours to obtain a modified monomer.

[0010] Furthermore, the molar ratio of octamethylcyclotetrasiloxane, tetramethyldisiloxane and tetramethylammonium hydroxide in step B1 is 2.4:1:2, the molar ratio of dihydrogen-terminated polysiloxane and acrylic acid is 1:2, and the amount of chloroplatinic acid is 1‰ of the mass of dihydrogen-terminated polysiloxane.

[0011] Furthermore, the molar ratio of the carboxylated polysiloxane, ethylene glycol amine and dicyclohexylcarbodiimide in step B2 is 1:2:2.1, and the amount ratio of the modified polysiloxane, phosphorus oxychloride and pyridine is 40 mmol:80 mmol:3.5 mL.

[0012] Beneficial effects of the invention: A flame-retardant and anti-ultraviolet PP plate disclosed by the invention comprises the following raw materials: PP masterbatch, a modified additive, silicon dioxide, zinc borate and zirconium oxide, wherein the modified additive is treated with sodium nitrite using dinitrobenzidine as a raw material to form a diazonium salt, the diazonium salt is reacted with resorcinol to obtain an azo compound, the azo compound is reduced to form a benzotriazole structure to obtain an intermediate 1, the intermediate 1 is reacted with di(4-nitrophenyl)phosphine oxychloride, so that the hydroxyl group on the intermediate 1 away from the benzotriazole reacts with the phosphorus oxychloride on the di(4-nitrophenyl)phosphine oxychloride to obtain an intermediate 2, the intermediate 2 is epoxidized with palladium carbon and hydrogen to convert the nitro group on the intermediate 1 into an amino group to obtain an intermediate 3, the intermediate 3, the modified monomer and urea are polymerized, so that the amino group on the intermediate 3, the phosphorus oxychloride on the modified monomer and the amino group on the urea are polymerized to obtain the modified additive.

[0013] The modified monomer is prepared by ring-opening condensation of octamethylcyclotetrasiloxane as a raw material, and then end-capping with tetramethyldisiloxane to obtain dihydrogen-terminated polysiloxane. The dihydrogen-terminated polysiloxane is reacted with acrylic acid so that the Si-H bond on the dihydrogen end reacts with the double bond on the acrylic acid to obtain carboxylated polysiloxane. The carboxylated polysiloxane is reacted with ethylene glycol amine under the action of dicyclohexylcarbodiimide so that the carboxyl group on the carboxylated polysiloxane and the imine on the ethylene glycol amine undergo a dehydration reaction to obtain the modified polysiloxane. The modified polysiloxane is reacted with phosphorus oxychloride so that the diol at both ends of the modified polysiloxane reacts with the two chlorine atom sites on the phosphorus oxychloride to obtain the modified monomer.

[0014] When the modified additive is exposed to light, the hydrogen bonds in the intramolecular hydrogen bond chelate ring formed by the hydroxyl group and the nitrogen on the triazole group in the modified additive molecule are broken or phototautomers are formed, and harmful ultraviolet light energy is converted into harmless heat energy and released. Silicon dioxide has high reflection and scattering capabilities, which can reduce the penetration of ultraviolet rays through the surface of the material. At the same time, the hydroxyl groups on the surface of silicon dioxide can capture free radicals excited by ultraviolet rays, thereby interrupting the photooxidation chain reaction. The combination with the modified additive can increase the anti-ultraviolet effect of the material. When burning, the modified additive can release amino groups, carbon dioxide and water vapor, thereby forming a porous silicon carbon layer on the surface of the material. The addition of zirconium oxide and zinc borate can strengthen the structure of the silicon carbon layer, thereby isolating oxygen and achieving a flame retardant effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0016] Figure 1 It is the 1H NMR spectrum of intermediate 3 in the present invention.

[0017] Figure 2 It is the 1H NMR spectrum of the modified monomer in the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example 1, a method for preparing a flame retardant and UV-resistant PP sheet, specifically comprising the following steps: Weigh the following raw materials in parts by weight: 80 parts of PP masterbatch, 8 parts of modifying additives, 5 parts of silicon dioxide, 3 parts of zinc borate and 3 parts of zirconium oxide, mix the raw materials and add them into an extruder, and extrude and press them under the conditions of 160°C in zone 1, 165°C in zone 2, 175°C in zone 3, 185°C in zone 4 and 180°C in die head to obtain a flame retardant and UV-resistant PP sheet.

[0020] The PP masterbatch model is HP501M.

[0021] The modified additive is prepared by the following steps: Step A1: Concentrated hydrochloric acid and deionized water are mixed, and dinitrobenzidine is added under the conditions of a rotation speed of 600 r / min and a temperature of 20° C., and the mixture is reacted for 30 minutes, and then the temperature is lowered to 0° C., sodium nitrite is added, and the mixture is reacted for 30 minutes to obtain a diazonium salt, and resorcinol, sodium carbonate and deionized water are mixed uniformly, and diazonium salt is added under the conditions of a rotation speed of 600 r / min and a temperature of 0° C., and the mixture is reacted for 2 hours to obtain an azo compound; Step A2: the azo compound, sodium hydroxide and deionized water are mixed uniformly, stirred at a speed of 60 r / min and a temperature of 70°C, thiourea dioxide is added, the temperature is raised to 80°C, the reaction is carried out for 3 hours, glacial acetic acid is added, and the filtrate is removed by filtration to obtain intermediate 1, intermediate 1, potassium carbonate and DMF are mixed, stirred at a speed of 200 r / min and a temperature of 80°C for 1 hour, di(4-nitrophenyl)phosphoryl chloride is added, and the reaction is continued for 5 hours to obtain intermediate 2; Step A3: Mix intermediate 2, palladium carbon catalyst and tetrahydrofuran evenly, introduce hydrogen to a standard atmospheric pressure, and react for 6 hours at a speed of 120 r / min and a temperature of 40°C to obtain intermediate 3. Mix intermediate 3, modified monomer, urea and DMF, and react for 5 hours at a speed of 150 r / min and a temperature of 60°C to obtain a modified additive.

[0022] The amount ratio of concentrated hydrochloric acid, deionized water, dinitrobenzidine and sodium nitrite described in step A1 is 25mL:20mL:5g:5.5g, the mass fraction of concentrated hydrochloric acid is 36%, and the amount ratio of resorcinol, sodium carbonate, deionized water and diazonium salt is 120mmol:8.5g:200mL:60mmol.

[0023] The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step A2 is 5 g:10 g:75 mL:1 g:25 mL, and the molar ratio of intermediate 1, potassium carbonate and di(4-nitrophenyl)phosphoryl chloride is 1:2.1:2.

[0024] The amount ratio of the intermediate 2, palladium carbon catalyst and tetrahydrofuran described in step A3 is 1 mmol:0.1 g:10 mL, and the molar ratio of the intermediate 3, modified monomer and urea is 1:5:4.

[0025] The modified monomer is prepared by the following steps: Step B1: octamethylcyclotetrasiloxane, tetramethyldisiloxane, tetramethylammonium hydroxide and dimethyl sulfoxide are mixed, nitrogen is introduced for protection, and the reaction is carried out for 10 hours at a speed of 120 r / min and a temperature of 90° C. to obtain a dihydrogen-terminated polysiloxane; the dihydrogen-terminated polysiloxane, acrylic acid, chloroplatinic acid and DMF are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 6 hours at a speed of 150 r / min and a temperature of 80° C. to obtain a carboxylated polysiloxane; Step B2: Carboxylated polysiloxane, ethylene glycol amine, dicyclohexylcarbodiimide and toluene are mixed, and the reaction is carried out at a speed of 300 r / min and a temperature of 30°C for 3 hours to obtain modified polysiloxane. The modified polysiloxane, phosphorus oxychloride and DMF are mixed evenly, and pyridine is added under stirring at a speed of 200 r / min and a temperature of 0°C. The temperature is raised to 25°C, and the reaction is carried out for 3 hours to obtain a modified monomer.

[0026] The molar ratio of octamethylcyclotetrasiloxane, tetramethyldisiloxane and tetramethylammonium hydroxide in step B1 is 2.4:1:2, the molar ratio of dihydrogen-terminated polysiloxane and acrylic acid is 1:2, and the amount of chloroplatinic acid used is 1‰ of the mass of dihydrogen-terminated polysiloxane.

[0027] The molar ratio of the carboxylated polysiloxane, ethylene glycol amine and dicyclohexylcarbodiimide described in step B2 is 1:2:2.1, and the amount ratio of the modified polysiloxane, phosphorus oxychloride and pyridine is 40mmol:80mmol:3.5mL.

[0028] Embodiment 2, a method for preparing a flame retardant and UV-resistant PP sheet, specifically comprising the following steps: Weigh the following raw materials in parts by weight: 90 parts of PP masterbatch, 9 parts of modifying additives, 8 parts of silicon dioxide, 4 parts of zinc borate and 4 parts of zirconium oxide, mix the raw materials and add them into an extruder, and extrude and press under the conditions of zone 1 temperature of 165°C, zone 2 temperature of 175°C, zone 3 temperature of 175°C, zone 4 temperature of 185°C and die head temperature of 185°C to obtain a flame retardant and UV-resistant PP sheet.

[0029] The PP masterbatch model is HP501M.

[0030] The modified additive is prepared by the following steps: Step A1: Concentrated hydrochloric acid and deionized water are mixed, and dinitrobenzidine is added under the conditions of a rotation speed of 600 r / min and a temperature of 25° C., and the mixture is reacted for 35 minutes, and then the temperature is lowered to 3° C., sodium nitrite is added, and the mixture is reacted for 35 minutes to obtain a diazonium salt, and resorcinol, sodium carbonate and deionized water are mixed uniformly, and diazonium salt is added under the conditions of a rotation speed of 600 r / min and a temperature of 5° C., and the mixture is reacted for 2 hours to obtain an azo compound; Step A2: the azo compound, sodium hydroxide and deionized water are mixed evenly, stirred at a speed of 60 r / min and a temperature of 75°C, thiourea dioxide is added, the temperature is raised to 80°C, the reaction is carried out for 4 hours, glacial acetic acid is added, and the filtrate is removed by filtration to obtain intermediate 1, intermediate 1, potassium carbonate and DMF are mixed, stirred at a speed of 200 r / min and a temperature of 85°C for 1 hour, di(4-nitrophenyl)phosphoryl chloride is added, and the reaction is continued for 6 hours to obtain intermediate 2; Step A3: Mix intermediate 2, palladium carbon catalyst and tetrahydrofuran evenly, introduce hydrogen to a standard atmospheric pressure, and react for 7 hours at a speed of 120 r / min and a temperature of 45°C to obtain intermediate 3. Mix intermediate 3, modified monomer, urea and DMF, and react for 5 hours at a speed of 150 r / min and a temperature of 65°C to obtain a modified additive.

[0031] The amount ratio of concentrated hydrochloric acid, deionized water, dinitrobenzidine and sodium nitrite described in step A1 is 25mL:20mL:5g:5.5g, the mass fraction of concentrated hydrochloric acid is 36%, and the amount ratio of resorcinol, sodium carbonate, deionized water and diazonium salt is 120mmol:8.5g:200mL:60mmol.

[0032] The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step A2 is 5 g:10 g:75 mL:1 g:25 mL, and the molar ratio of intermediate 1, potassium carbonate and di(4-nitrophenyl)phosphoryl chloride is 1:2.1:2.

[0033] The amount ratio of the intermediate 2, palladium carbon catalyst and tetrahydrofuran described in step A3 is 1 mmol:0.1 g:10 mL, and the molar ratio of the intermediate 3, modified monomer and urea is 1:5:4.

[0034] The modified monomer is prepared by the following steps: Step B1: octamethylcyclotetrasiloxane, tetramethyldisiloxane, tetramethylammonium hydroxide and dimethyl sulfoxide are mixed, nitrogen is introduced for protection, and the reaction is carried out for 12 hours at a speed of 120 r / min and a temperature of 95° C. to obtain a dihydrogen-terminated polysiloxane; the dihydrogen-terminated polysiloxane, acrylic acid, chloroplatinic acid and DMF are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 7 hours at a speed of 150 r / min and a temperature of 85° C. to obtain a carboxylated polysiloxane; Step B2: Carboxylated polysiloxane, ethylene glycol amine, dicyclohexylcarbodiimide and toluene are mixed, and the reaction is carried out at a speed of 300 r / min and a temperature of 35°C for 4 hours to obtain modified polysiloxane. The modified polysiloxane, phosphorus oxychloride and DMF are mixed evenly, and pyridine is added under stirring at a speed of 200 r / min and a temperature of 3°C. The temperature is raised to 25°C, and the reaction is carried out for 4 hours to obtain a modified monomer.

[0035] The molar ratio of octamethylcyclotetrasiloxane, tetramethyldisiloxane and tetramethylammonium hydroxide in step B1 is 2.4:1:2, the molar ratio of dihydrogen-terminated polysiloxane and acrylic acid is 1:2, and the amount of chloroplatinic acid used is 1‰ of the mass of dihydrogen-terminated polysiloxane.

[0036] The molar ratio of the carboxylated polysiloxane, ethylene glycol amine and dicyclohexylcarbodiimide described in step B2 is 1:2:2.1, and the amount ratio of the modified polysiloxane, phosphorus oxychloride and pyridine is 40mmol:80mmol:3.5mL.

[0037] Embodiment 3, a method for preparing a flame retardant and UV-resistant PP sheet, specifically comprising the following steps: Weigh the following raw materials in parts by weight: 100 parts of PP masterbatch, 10 parts of modifying additives, 10 parts of silica, 5 parts of zinc borate and 5 parts of zirconium oxide, mix the raw materials and add them into an extruder, and extrude and press at a temperature of 165°C in zone 1, 175°C in zone 2, 185°C in zone 3, 195°C in zone 4 and 185°C in die head to obtain a flame retardant and UV-resistant PP sheet.

[0038] The PP masterbatch model is HP501M.

[0039] The modified additive is prepared by the following steps: Step A1: Concentrated hydrochloric acid and deionized water are mixed, and dinitrobenzidine is added under the conditions of a rotation speed of 800 r / min and a temperature of 25° C., and the mixture is reacted for 40 minutes, and then the temperature is lowered to 5° C., sodium nitrite is added, and the mixture is reacted for 40 minutes to obtain a diazonium salt, and resorcinol, sodium carbonate and deionized water are mixed uniformly, and diazonium salt is added under the conditions of a rotation speed of 800 r / min and a temperature of 5° C., and the mixture is reacted for 3 hours to obtain an azo compound; Step A2: the azo compound, sodium hydroxide and deionized water are mixed uniformly, stirred at a speed of 80 r / min and a temperature of 75°C, thiourea dioxide is added, the temperature is raised to 85°C, the reaction is carried out for 4 hours, glacial acetic acid is added, and the filtrate is removed by filtration to obtain intermediate 1, intermediate 1, potassium carbonate and DMF are mixed, stirred at a speed of 300 r / min and a temperature of 85°C for 1.5 hours, di(4-nitrophenyl)phosphoryl chloride is added, and the reaction is continued for 7 hours to obtain intermediate 2; Step A3: Mix intermediate 2, palladium carbon catalyst and tetrahydrofuran evenly, introduce hydrogen to a standard atmospheric pressure, and react for 8 hours at a speed of 150 r / min and a temperature of 50°C to obtain intermediate 3. Mix intermediate 3, modified monomer, urea and DMF, and react for 6 hours at a speed of 200 r / min and a temperature of 65°C to obtain a modified additive.

[0040] The amount ratio of concentrated hydrochloric acid, deionized water, dinitrobenzidine and sodium nitrite described in step A1 is 25mL:20mL:5g:5.5g, the mass fraction of concentrated hydrochloric acid is 36%, and the amount ratio of resorcinol, sodium carbonate, deionized water and diazonium salt is 120mmol:8.5g:200mL:60mmol.

[0041] The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step A2 is 5 g:10 g:75 mL:1 g:25 mL, and the molar ratio of intermediate 1, potassium carbonate and di(4-nitrophenyl)phosphoryl chloride is 1:2.1:2.

[0042] The amount ratio of the intermediate 2, palladium carbon catalyst and tetrahydrofuran described in step A3 is 1 mmol:0.1 g:10 mL, and the molar ratio of the intermediate 3, modified monomer and urea is 1:5:4.

[0043] The modified monomer is prepared by the following steps: Step B1: octamethylcyclotetrasiloxane, tetramethyldisiloxane, tetramethylammonium hydroxide and dimethyl sulfoxide are mixed, nitrogen is introduced for protection, and the reaction is carried out for 12 hours at a speed of 150 r / min and a temperature of 95° C. to obtain a dihydrogen-terminated polysiloxane; the dihydrogen-terminated polysiloxane, acrylic acid, chloroplatinic acid and DMF are mixed evenly, nitrogen is introduced for protection, and the reaction is carried out for 8 hours at a speed of 200 r / min and a temperature of 85° C. to obtain a carboxylated polysiloxane; Step B2: Carboxylated polysiloxane, ethylene glycol amine, dicyclohexylcarbodiimide and toluene are mixed, and the reaction is carried out at a speed of 500 r / min and a temperature of 35°C for 5 hours to obtain modified polysiloxane. The modified polysiloxane, phosphorus oxychloride and DMF are mixed evenly, and pyridine is added under stirring at a speed of 300 r / min and a temperature of 3°C. The temperature is raised to 30°C, and the reaction is carried out for 4 hours to obtain a modified monomer.

[0044] The molar ratio of octamethylcyclotetrasiloxane, tetramethyldisiloxane and tetramethylammonium hydroxide in step B1 is 2.4:1:2, the molar ratio of dihydrogen-terminated polysiloxane and acrylic acid is 1:2, and the amount of chloroplatinic acid used is 1‰ of the mass of dihydrogen-terminated polysiloxane.

[0045] The molar ratio of the carboxylated polysiloxane, ethylene glycol amine and dicyclohexylcarbodiimide described in step B2 is 1:2:2.1, and the amount ratio of the modified polysiloxane, phosphorus oxychloride and pyridine is 40mmol:80mmol:3.5mL.

[0046] Figure 1 The small peak at the chemical shift of 10.01 is a single peak attributed to the hydroxyl group, the single peak at the chemical shift of 5.50 is attributed to the amino group, and several medium-height peaks between the chemical shifts of 6 and 8 correspond to the hydrogen atoms on the aromatic ring. Figure 2 There is a smaller peak near chemical shift 1, which is the hydrogen atom on the alkyl chain. The peak near chemical shift 2 is the hydrogen atom close to the carbonyl group on the alkyl chain. The peaks near chemical shifts 3.5 and 4.5 are the hydrogen atoms close to the oxygen atom on the alkyl chain.

[0047] Comparative Example 1: Compared with Example 1, no silicon dioxide was added in this comparative example, and the remaining steps were the same.

[0048] Comparative Example 2: Compared with Example 1, zinc borate was not added in this comparative example, and the remaining steps were the same.

[0049] Comparative Example 3: Compared with Example 1, zirconium oxide was not added in this comparative example, and the remaining steps were the same.

[0050] Comparative Example 4: Compared with Example 1, hydroquinone is used to replace intermediate 1, and the remaining steps are the same.

[0051] Comparative Example 5: Compared with Example 1, pentaerythritol is used to replace the modified polysiloxane, and the remaining steps are the same.

[0052] The PP sheets obtained in Comparative Examples 1-3 and 1-5 were made into 168 mm × 13 mm × 3.2 mm specimens according to the standard of GB / T1040.3-2006, and the tensile speed was 50 mm / min. The initial tensile strength was tested according to the standard of GB / T16422.3-2022 with an irradiation intensity of 600 W / m 2 The cumulative irradiation is 400kWh / m 2 , to detect the decrease rate of tensile strength after light aging, a 125mm×13mm×10mm sample was made according to the standard of GB / T2408-2008, and the vertical burning level was tested. A 130mm×10mm×10mm sample was made according to the standard of GB / T2406.2-2009, and the limiting oxygen index was tested. The test results are described in Table 1 below.

[0053] Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Initial tensile strength MPa 42.18 43.31 44.36 41.02 42.12 41.11 41.13 42.07 Tensile strength decrease rate after aging % 2.93 2.85 2.81 9.28 3.13 3.35 33.71 2.95 Vertical burning level V0 V0 V0 V1 V0 V0 V0 V1 Limiting oxygen index% 37.15 37.36 38.93 34.04 35.28 34.87 37.06 32.75 It can be seen from Table 1 that the present invention has good UV resistance and flame retardant effects.

[0054] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a flame retardant and UV-resistant PP sheet, characterized in that: The specific steps include: Weigh the following raw materials in parts by weight: 80-100 parts of PP masterbatch, 8-10 parts of modified additives, 5-10 parts of silicon dioxide, 3-5 parts of zinc borate and 3-5 parts of zirconium oxide, mix the raw materials and add them into an extruder, extrude and press them to obtain a flame-retardant and UV-resistant PP sheet.

2. The method for preparing a flame retardant and UV-resistant PP sheet according to claim 1, characterized in that: The modified additive is prepared by the following steps: Step A1: Concentrated hydrochloric acid and deionized water are mixed, stirred and dinitrobenzidine is added to react, then the temperature is lowered and sodium nitrite is added to react to obtain a diazonium salt, resorcinol, sodium carbonate and deionized water are mixed, stirred and diazonium salt is added to react to obtain an azo compound; Step A2: an azo compound, sodium hydroxide and deionized water are mixed and stirred, and thiourea dioxide is added to react, glacial acetic acid is added, and the filtrate is filtered to obtain intermediate 1, intermediate 1, potassium carbonate and DMF are mixed and stirred, di(4-nitrophenyl)phosphinoyl chloride is added, and the reaction is continued for 5-7 hours to obtain intermediate 2; Step A3: The intermediate 2, the palladium carbon catalyst and tetrahydrofuran are mixed evenly, and hydrogen is introduced to a standard atmospheric pressure to react to obtain the intermediate 3. The intermediate 3, the modified monomer, urea and DMF are mixed and reacted to obtain the modified additive.

3. The method for preparing a flame retardant and UV-resistant PP sheet according to claim 2, characterized in that: The amount ratio of concentrated hydrochloric acid, deionized water, dinitrobenzidine and sodium nitrite in step A1 is 25mL:20mL:5g:5.5g, and the amount ratio of resorcinol, sodium carbonate, deionized water and diazonium salt is 120mmol:8.5g:200mL:60mmol.

4. The method for preparing a flame retardant and UV-resistant PP sheet according to claim 2, characterized in that: The amount ratio of the azo compound, sodium hydroxide, deionized water, thiourea dioxide and glacial acetic acid in step A2 is 5 g:10 g:75 mL:1 g:25 mL, and the molar ratio of intermediate 1, potassium carbonate and di(4-nitrophenyl)phosphoryl chloride is 1:2.1:

2.

5. The method for preparing a flame retardant and UV-resistant PP sheet according to claim 2, characterized in that: The amount ratio of the intermediate 2, palladium carbon catalyst and tetrahydrofuran described in step A3 is 1 mmol:0.1 g:10 mL, and the molar ratio of the intermediate 3, modified monomer and urea is 1:5:

4.

6. The method for preparing a flame retardant and UV-resistant PP sheet according to claim 2, characterized in that: The modified monomer is prepared by the following steps: Step B1: octamethylcyclotetrasiloxane, tetramethyldisiloxane, tetramethylammonium hydroxide and dimethyl sulfoxide are mixed, nitrogen is introduced for protection, and the mixture is reacted to obtain dihydrogen-terminated polysiloxane; dihydrogen-terminated polysiloxane, acrylic acid, chloroplatinic acid and DMF are uniformly mixed, nitrogen is introduced for protection, and the mixture is reacted to obtain carboxylated polysiloxane; Step B2: Carboxylated polysiloxane, ethylene glycol amine, dicyclohexylcarbodiimide and toluene are mixed and reacted to obtain modified polysiloxane, and the modified polysiloxane, phosphorus oxychloride and DMF are mixed and stirred and pyridine is added to react to obtain a modified monomer.

7. The method for preparing a flame retardant and UV-resistant PP sheet according to claim 6, characterized in that: The molar ratio of octamethylcyclotetrasiloxane, tetramethyldisiloxane and tetramethylammonium hydroxide in step B1 is 2.4:1:2, and the molar ratio of dihydrogen-terminated polysiloxane and acrylic acid is 1:

2.

8. The method for preparing a flame retardant and UV-resistant PP sheet according to claim 6, characterized in that: The molar ratio of the carboxylated polysiloxane, ethylene glycol amine and dicyclohexylcarbodiimide described in step B2 is 1:2:2.1, and the amount ratio of the modified polysiloxane, phosphorus oxychloride and pyridine is 40mmol:80mmol:3.5mL.

Images