Antistatic flame-retardant functional masterbatch and preparation method thereof

Abstract

This invention discloses an antistatic and flame-retardant functional masterbatch and its preparation method, relating to the field of plastics technology. The antistatic and flame-retardant functional masterbatch prepared by this invention includes a self-made antistatic agent, a composite flame retardant, polypropylene, filler, surface modifier, lubricant, dispersant, antioxidant, and toughening agent. The self-made antistatic agent is prepared by reacting a network-crosslinked isocyanate with double-terminated carboxyl polyethylene glycol, followed by crosslinking with copolymerized polyamic acid. This not only achieves long-lasting antistatic properties but also forms a crosslinked structure in the masterbatch during co-extrusion with the composite flame retardant, synergistically enhancing flame-retardant performance. The composite flame retardant includes benzylamine-modified melamine and sulfonyl diamine-modified melamine, giving the masterbatch excellent flame-retardant properties.

Description

Technical Field

[0001] This invention relates to the field of plastics technology, specifically to an antistatic and flame-retardant functional masterbatch and its preparation method. Background Technology

[0002] Masterbatch refers to the granular material produced during plastic processing and molding by mixing various additives, fillers, and a small amount of carrier resin for ease of operation. This mixture is then processed through equipment such as extruders, involving metering, mixing, melting, extrusion, and pelletizing. Masterbatch consists of carrier resin, various fillers, and various additives. The limits of additives or filler content in masterbatch are several to ten times higher than the required amount in the actual plastic product. During molding and processing, the ratio of masterbatch to matrix resin must be adjusted according to the content of relevant components in the masterbatch and the amount required in the actual product.

[0003] Masterbatch is a raw material for plastic production. Existing plastic products have poor antistatic properties during use, causing discomfort to users; at the same time, existing plastic products have poor flame retardancy and other properties. Therefore, this invention studies and prepares a functional masterbatch with excellent antistatic and flame retardant properties to solve this problem. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an antistatic and flame-retardant functional masterbatch and its preparation method.

[0005] The present invention proposes a technical solution to solve the above-mentioned technical problems: an antistatic and flame-retardant functional masterbatch, comprising the following raw material components in parts by weight: 2-5 parts of self-made antistatic agent, 1-3 parts of composite flame retardant, 100-120 parts of polypropylene, 280-320 parts of filler, 1-2 parts of surface modifier, 6-8 parts of lubricant, 2-3 parts of dispersant, 0.1-0.2 parts of antioxidant and 4-8 parts of toughening agent; wherein the self-made antistatic agent is prepared by reacting a network crosslinked isocyanate with double-terminated carboxyl polyethylene glycol, and then crosslinking it with copolymerized polyamic acid.

[0006] Preferably, the network crosslinked isocyanate is prepared by reacting hydroxyl-terminated polybutadiene, 4,4′,4″-triphenylmethane triisocyanate, and 1-chloro-2,4-dinitrobenzene; the copolymerized polyamic acid is prepared by reacting 2,2'-bis(trifluoromethyl)benzidine, 4,4'-(hexafluoroisopropylidene)phthalic anhydride, and pyromellitic dianhydride.

[0007] Preferably, the composite flame retardant includes benzylamine-modified melamine and sulfonyldiamine-modified melamine; the benzylamine-modified melamine is prepared by reacting hexahydroxymethyl melamine with o-hydroxy-N-methylbenzylamine; the sulfonyldiamine-modified melamine is prepared by reacting hexahydroxymethyl melamine with N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine.

[0008] Preferably, the filler is calcium carbonate; the surface modifier is polyethylene wax; the lubricant is polyethylene wax; the dispersant is calcium stearate; the antioxidant is B215; and the toughening agent is either POE or EVA.

[0009] Preferably, the preparation method of the antistatic and flame-retardant functional masterbatch includes the following specific steps: S1. Under a nitrogen atmosphere, cross-linked isocyanate, bi-carboxyl-terminated polyethylene glycol, and dichloromethane are dissolved by stirring at a mass ratio of 1:2:20-30. Then, 0.01-0.03 times the mass of the cross-linked isocyanate (4-dimethylaminopyridine) is added. The mixture is placed in an ice bath at 0-5°C. Next, 0.06-0.08 times the mass of the cross-linked isocyanate (dicyclohexylcarbodiimide) is added. The reaction is carried out for 1-2 hours, then heated to room temperature and reacted for 20-24 hours. The mixture is filtered and precipitated with ethanol. After vacuum filtration, it is combined with copolymers. Polyamic acid of type 1 was mixed at a mass ratio of 1~3:10, stirred at 200~400 rpm for 1~2 hours, heated to 80~82℃ and reacted for 50~60 minutes, heated to 120~122℃ and reacted for 50~60 minutes, heated to 180~182℃ and reacted for 50~60 minutes, heated to 250~252℃ and reacted for 50~60 minutes, heated to 300~302℃ and reacted for 50~60 minutes, and then cooled to room temperature to obtain a self-made antistatic agent. S2. Mix isopropanol and hexamethylol melamine at a mass ratio of 20-30:3, heat to 70-80℃, stir evenly, add o-hydroxy-N-methylbenzylamine at 1.2-1.3 times the mass of hexamethylol melamine, and p-toluenesulfonic acid catalyst at 0.001-0.003 times the mass of hexamethylol melamine, heat to 80-100℃, reflux for 4-6 hours, cool to 60-70℃, and adjust the pH to 7-8 with triethylamine to obtain benzylamine-modified melamine; S3. Under a nitrogen atmosphere, N,N-dimethylformamide and hexamethylol melamine are mixed at a mass ratio of 20:1~2, heated to 60~70℃, stirred and dissolved, and then N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine (1.2~1.4 times the mass of hexamethylol melamine) and formic acid (0.001~0.002 times the mass of hexamethylol melamine) are added as a catalyst. The mixture is heated to 80~100℃ and refluxed for 4~8 hours. The precipitate is obtained with ethanol, filtered, washed with ethanol 5~8 times, and dried in a vacuum oven at 60~80℃ for 12~24 hours to obtain sulfonyldiamine modified melamine. S4. Mix benzylamine-modified melamine and sulfonyl diamine-modified melamine to prepare a composite flame retardant; S5. By weight, place the filler and surface modifier in a mixer, heat to 120~150℃, mix at 1500~1700rpm for 3~5min, cool to 105~115℃, add self-made antistatic agent, composite flame retardant, polypropylene, lubricant, dispersant, antioxidant and toughening agent, continue mixing for 2~4min, heat to 160~170℃, continue mixing for 4~6min, melt extrusion granulation to obtain antistatic and flame retardant functional masterbatch.

[0010] Preferably, in step S1 above, the preparation method of the network cross-linked isocyanate is as follows: Under a nitrogen atmosphere, hydroxyl-terminated polybutadiene and dichloromethane are mixed at a mass ratio of 1:2~2.2, stirred and dissolved, and then sodium hydroxide is added at a mass ratio of 0.3~0.32 times that of hydroxyl-terminated polybutadiene. The activation reaction is continued for 20~30 min. A dichloromethane solution of 1-chloro-2,4-dinitrobenzene with a mass fraction of 40~50% is added dropwise at a rate of 1~3 ml / min at a mass ratio of 0.3~0.4 times that of hydroxyl-terminated polybutadiene. The reaction is continued for 12~24 h. Then, 4,4′,4″-triphenylmethane triisocyanate at a mass ratio of 1~1.2 times that of hydroxyl-terminated polybutadiene and stannous octoate catalyst at a mass ratio of 0.001~0.002 times that of hydroxyl-terminated polybutadiene are added. After stirring evenly, the mixture is allowed to stand to remove bubbles and then transferred to an oven at 60~80℃ for curing for 6~12 h to obtain the network cross-linked isocyanate.

[0011] Preferably, in step S1 above, the preparation method of the copolymer polyamic acid is as follows: under a nitrogen atmosphere, N-methylpyrrolidone and 2,2'-bis(trifluoromethyl)benzidine are mixed at a mass ratio of 25:6~8, heated to 30~32°C, stirred and dissolved, then 0.16~0.18 times the mass of N-methylpyrrolidone of 4,4'-(hexafluoroisopropylidene) diaphthalic anhydride is added, the temperature is raised to 40~42°C, and the reaction is carried out for 2~3 hours. Then, 0.08~0.1 times the mass of N-methylpyrrolidone of pyromellitic dianhydride is added, the temperature is raised to 80~82°C, and the reaction is carried out for 50~70 minutes. Finally, N-methylpyrrolidone is added again, and the solid content is adjusted to 18~20% to obtain the copolymer polyamic acid.

[0012] Preferably, in step S2 above, the preparation method of o-hydroxy-N-methylbenzylamine is as follows: methanol and o-hydroxybenzaldehyde are mixed at a mass ratio of 20:1~1.2, stirred and dissolved, and then placed in an ice bath to cool to 0~5℃. A 33% methylamine methanol solution with a mass fraction of 5.2~5.4 times that of o-hydroxybenzaldehyde is added dropwise at a rate of 1~3 ml / min. The pH is adjusted to 5~6 with glacial acetic acid, and then sodium cyanoborohydride with a mass fraction of 0.4~0.6 times that of o-hydroxybenzaldehyde is added. The mixture is heated to room temperature and reacted for 4~6 h. Ice water with a mass fraction of 50 times that of o-hydroxybenzaldehyde is added, and the pH is adjusted to 9~10 with sodium hydroxide. The mixture is extracted with ethyl acetate, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure, and then subjected to silica gel column chromatography with petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain o-hydroxy-N-methylbenzylamine.

[0013] Preferably, in step S3 above, the preparation method of N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyl diamine is as follows: Under a nitrogen atmosphere, N-(2,4-difluorophenyl)-4-nitrobenzenesulfonamide and N,N-dimethylformamide are mixed at a mass ratio of 1~3:20. After stirring evenly, 0.07~0.09 times the mass of N,N-dimethylformamide of potassium carbonate and 0.04~0.06 times the mass of N,N-dimethylformamide of 4-fluoroaniline are added. The temperature is raised to 80~90℃, and the reaction is carried out for 12~24h. The temperature is lowered to 0~5℃, and the mixture is extracted with ethyl acetate, washed with saturated brine, dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyl diamine.

[0014] Preferably, in step S4 above, the mass ratio of benzylamine-modified melamine to sulfonyl diamine-modified melamine is 1:1~3.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: The antistatic and flame-retardant functional masterbatch prepared by this invention includes a self-made antistatic agent, a composite flame retardant, polypropylene, filler, surface modifier, lubricant, dispersant, antioxidant, and toughening agent. The homemade antistatic agent is prepared by reacting a network-crosslinked isocyanate with bi-carboxyl-terminated polyethylene glycol, followed by crosslinking with a copolymeric polyamic acid. The network-crosslinked isocyanate is prepared by reacting hydroxyl-terminated polybutadiene, 4,4′,4″-triphenylmethane triisocyanate, and 1-chloro-2,4-dinitrobenzene. The copolymeric polyamic acid is prepared by reacting 2,2'-bis(trifluoromethyl)benzidine, 4,4'-(hexafluoroisopropylidene)phthalic anhydride, and pyromellitic dianhydride. The hydroxyl groups of the network-crosslinked isocyanate react with bi-carboxyl-terminated polyethylene glycol. After the carboxyl-terminated polyethylene glycol reacts, polyethylene oxide is introduced onto the side chain, and the isocyanate group crosslinks with the copolymer polyamic acid to form a permanent polymeric antistatic agent. This not only prevents the antistatic agent from migrating or precipitating too quickly to the surface, achieving long-lasting antistatic properties, but also forms a conductive water film, providing ion conduction channels to quickly dissipate static charge and further enhance antistatic properties. When co-extruded with composite flame retardants, a crosslinked structure is formed in the masterbatch, synergistically enhancing flame retardant performance. Composite flame retardants include benzylamine-modified melamine and sulfonyldiamine-modified melamine. Benzylamine-modified melamine is prepared by reacting hexamethylol melamine with o-hydroxy-N-methylbenzylamine, while sulfonyldiamine-modified melamine is prepared by reacting hexamethylol melamine with N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine. The introduction of benzylamine side chains containing benzene rings and tertiary amine groups into the melamine structure not only enhances the compatibility of the flame retardant with the polymer matrix, but also allows the tertiary amine groups to promote char formation and capture free radicals during combustion. By grafting sulfonamide structures containing fluorine, nitro, and sulfonamide onto melamine rings, the introduction of fluorine can reduce the surface energy of the material and form a flame-retardant barrier, while the nitro can decompose at high temperatures to produce nitrogen-containing flame-retardant gases. The introduced sulfonamide further enhances the thermal stability of the flame retardant. After the two modified melamines are combined, through synergistic effects, they can release inert gases in the gas phase to dilute the concentration of combustible gases and inhibit the combustion reaction, and promote the formation of a dense and stable char layer in the condensed phase to isolate heat and oxygen transfer, thereby giving the masterbatch excellent flame-retardant properties. Detailed Implementation

[0016] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those skilled in the art.

[0017] To more clearly illustrate the method provided by the present invention, the following embodiments will be used to describe in detail the test methods for various indicators of the composite material for puncture-resistant new energy battery bottom protection plates prepared in the embodiments and comparative examples: Antistatic properties: The surface resistivity of the antistatic and flame-retardant functional masterbatches prepared in the examples and comparative examples was tested in accordance with GB / T 1410.

[0018] Flame retardancy: The antistatic and flame-retardant functional masterbatches prepared in the examples and comparative examples were tested for oxygen index in accordance with GB / T 2406.2. Example 1

[0019] The raw materials of the antistatic and flame-retardant functional masterbatch in this embodiment are: 2 parts homemade antistatic agent, 1 part composite flame retardant, 100 parts polypropylene, 280 parts filler calcium carbonate, 1 part surface modifier polyethylene wax, 6 parts lubricant polyethylene wax, 2 parts dispersant calcium stearate, 0.1 parts antioxidant B215 and 4 parts toughening agent POE. The preparation method of the antistatic and flame-retardant functional masterbatch in this embodiment is as follows: S1. Under a nitrogen atmosphere, hydroxyl-terminated polybutadiene and dichloromethane are mixed at a mass ratio of 1:2 and stirred until dissolved. Then, sodium hydroxide (0.3 times the mass of the hydroxyl-terminated polybutadiene) is added, and the reaction is continued for 20 min to activate the reaction. A 40% dichloromethane solution of 1-chloro-2,4-dinitrobenzene (0.3 times the mass of the hydroxyl-terminated polybutadiene) is added dropwise at a rate of 1 ml / min. The reaction is continued for 12 h. Finally, 4,4′,4″-triphenylmethane triisocyanate (1 times the mass of the hydroxyl-terminated polybutadiene) is added. Stannous octoate catalyst, in 0.001 times the mass of ester and hydroxyl-terminated polybutadiene, was stirred until homogeneous, allowed to stand to degas, and then transferred to a 60°C oven for curing for 6 hours to obtain a network crosslinked isocyanate. Under a nitrogen atmosphere, N-methylpyrrolidone and 2,2'-bis(trifluoromethyl)benzidine were mixed at a mass ratio of 25:6, heated to 30°C, stirred until dissolved, and then 4,4'-(hexafluoroisopropylidene) phthalic anhydride, in 0.16 times the mass of N-methylpyrrolidone, were added. The mixture was heated to 40°C and reacted for 2 hours. Then, [the remaining text is incomplete and requires further context to translate accurately.] 0.08 times the mass of N-methylpyrrolidone and pyromellitic dianhydride were added, heated to 80°C, and reacted for 50 min. Then, N-methylpyrrolidone was added to adjust the solid content to 18% to obtain a copolymerized polyamic acid. Under a nitrogen atmosphere, cross-linked isocyanate, bi-carboxyl-terminated polyethylene glycol, and dichloromethane were dissolved by stirring at a mass ratio of 1:2:20. Then, 0.01 times the mass of cross-linked isocyanate and 4-dimethylaminopyridine were added. The mixture was placed in an ice bath at 0°C, and then 0.01 times the mass of cross-linked isocyanate was added. Dicyclohexylcarbodiimide was reacted at a ratio of 0.6:1 for 1 hour, then heated to room temperature and reacted for 20 hours. The mixture was filtered and precipitated with ethanol. After filtration, it was mixed with copolymerized polyamic acid at a mass ratio of 1:10. The mixture was stirred at 200 rpm for 1 hour, heated to 80°C and reacted for 50 minutes, then heated to 120°C and reacted for 50 minutes, then heated to 180°C and reacted for 50 minutes, then heated to 250°C and reacted for 50 minutes, then heated to 300°C and reacted for 50 minutes. The mixture was then cooled to room temperature to obtain a self-made antistatic agent. S2. Mix methanol and o-hydroxybenzaldehyde at a mass ratio of 20:1, stir to dissolve, and cool to 0°C in an ice bath. Add 5.2 times the mass of o-hydroxybenzaldehyde in a 33% methylamine methanol solution at a rate of 1 ml / min. Adjust the pH to 5 with glacial acetic acid, then add 0.4 times the mass of o-hydroxybenzaldehyde in sodium cyanoborohydride. Heat to room temperature and react for 4 hours. Add 50 times the mass of o-hydroxybenzaldehyde in ice water, adjust the pH to 9 with sodium hydroxide, extract with ethyl acetate, dry to anhydrous sodium sulfate, filter, and concentrate under reduced pressure. The mixture was then subjected to silica gel column chromatography with petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain o-hydroxy-N-methylbenzylamine. Isopropanol and hexamethylol melamine were mixed at a mass ratio of 20:3, heated to 70°C, stirred until homogeneous, and then 1.2 times the mass of o-hydroxy-N-methylbenzylamine and 0.001 times the mass of hexamethylol melamine catalyst p-toluenesulfonic acid were added. The mixture was heated to 80°C, refluxed for 4 hours, cooled to 60°C, and the pH was adjusted to 7 with triethylamine to obtain benzylamine-modified melamine. S3. Under a nitrogen atmosphere, N-(2,4-difluorophenyl)-4-nitrobenzenesulfonamide and N,N-dimethylformamide were mixed at a mass ratio of 1:20 and stirred until homogeneous. Then, potassium carbonate (0.07 times the mass of N,N-dimethylformamide) and 4-fluoroaniline (0.04 times the mass of N,N-dimethylformamide) were added. The mixture was heated to 80°C and reacted for 12 hours. The mixture was then cooled to 0°C, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl). Sulfodiamine; Under a nitrogen atmosphere, N,N-dimethylformamide and hexamethylol melamine were mixed at a mass ratio of 20:1, heated to 60°C, stirred and dissolved, and then N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine (1.2 times the mass of hexamethylol melamine) and formic acid (0.001 times the mass of hexamethylol melamine) were added as a catalyst. The mixture was heated to 80°C and refluxed for 4 hours. The precipitate was obtained by precipitating with ethanol, filtering, washing with ethanol 5 times, and drying in a vacuum oven at 60°C for 12 hours to obtain sulfonyldiamine-modified melamine. S4. Mix benzylamine-modified melamine and sulfonyl diamine-modified melamine at a mass ratio of 1:1 to prepare a composite flame retardant; S5. By weight, place the filler and surface modifier in a mixer, heat to 120°C, mix at 1500 rpm for 3 min, cool to 105°C, add self-made antistatic agent, composite flame retardant, polypropylene, lubricant, dispersant, antioxidant and toughening agent, continue mixing for 2 min, heat to 160°C, continue mixing for 4~6 min, melt extrusion granulation to obtain antistatic and flame retardant functional masterbatch. Example 2

[0020] The raw materials of the antistatic and flame-retardant functional masterbatch in this embodiment are: 3.5 parts of homemade antistatic agent, 2 parts of composite flame retardant, 110 parts of polypropylene, 300 parts of filler calcium carbonate, 1.5 parts of surface modifier polyethylene wax, 7 parts of lubricant polyethylene wax, 2.5 parts of dispersant calcium stearate, 0.15 parts of antioxidant B215 and 6 parts of toughening agent POE. The preparation method of the antistatic and flame-retardant functional masterbatch in this embodiment is as follows: S1. Under a nitrogen atmosphere, hydroxyl-terminated polybutadiene and dichloromethane were mixed at a mass ratio of 1:2.1 and stirred until dissolved. Then, sodium hydroxide (0.31 times the mass of the hydroxyl-terminated polybutadiene) was added, and the reaction was continued for 25 min to activate the reaction. A 45% dichloromethane solution of 1-chloro-2,4-dinitrobenzene (0.35 times the mass of the hydroxyl-terminated polybutadiene) was added dropwise at a rate of 2 ml / min. The reaction was continued for 18 h. Finally, 4,4′,4″-triphenylmethane (1.1 times the mass of the hydroxyl-terminated polybutadiene) was added. Isocyanate and stannous octoate catalyst (0.0015 times the mass of hydroxyl-terminated polybutadiene) were stirred until homogeneous, allowed to stand to remove bubbles, and then transferred to a 70°C oven for curing for 9 hours to obtain a network crosslinked isocyanate. Under a nitrogen atmosphere, N-methylpyrrolidone and 2,2'-bis(trifluoromethyl)benzidine were mixed at a mass ratio of 25:7, heated to 31°C, stirred until dissolved, and then 4,4'-(hexafluoroisopropylidene)diaphthalic anhydride (0.17 times the mass of N-methylpyrrolidone) were added. The mixture was then heated to 41°C and reacted for 2.5 hours. Add 0.09 times the mass of N-methylpyrrolidone to pyromellitic dianhydride, heat to 81℃, react for 60 min, then add N-methylpyrrolidone again to adjust the solid content to 19%, thus obtaining a copolymerized polyamic acid. Under a nitrogen atmosphere, dissolve cross-linked isocyanate, bi-carboxyl-terminated polyethylene glycol, and dichloromethane in a mass ratio of 1:2:25 by stirring. Add 0.02 times the mass of cross-linked isocyanate to 4-dimethylaminopyridine, place in an ice bath at 3℃, and then add 0.0 times the mass of cross-linked isocyanate. Seven times the amount of dicyclohexylcarbodiimide was reacted for 1.5 h, then heated to room temperature and reacted for 22 h. The mixture was filtered and precipitated with ethanol. After filtration, it was mixed with copolymerized polyamic acid at a mass ratio of 2:10. The mixture was stirred at 300 rpm for 1.5 h, heated to 81 °C and reacted for 55 min, then heated to 121 °C and reacted for 55 min, then heated to 181 °C and reacted for 55 min, then heated to 251 °C and reacted for 55 min, then heated to 301 °C and reacted for 55 min, and finally cooled to room temperature to obtain the self-made antistatic agent. S2. Methanol and o-hydroxybenzaldehyde were mixed at a mass ratio of 20:1.1 and stirred until dissolved. The mixture was then cooled to 4°C in an ice bath. A 33% methylamine methanol solution (5.3 times the mass of o-hydroxybenzaldehyde) was added dropwise at a rate of 2 ml / min. The pH was adjusted to 5.5 with glacial acetic acid. Then, sodium cyanoborohydride (0.5 times the mass of o-hydroxybenzaldehyde) was added. The mixture was heated to room temperature and reacted for 5 hours. Ice water (50 times the mass of o-hydroxybenzaldehyde) was added, and the pH was adjusted to 9.5 with sodium hydroxide. The mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The mixture was condensed and then subjected to silica gel column chromatography with petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain o-hydroxy-N-methylbenzylamine. Isopropanol and hexamethylol melamine were mixed at a mass ratio of 25:3, heated to 75°C, stirred until homogeneous, and then 1.25 times the mass of o-hydroxy-N-methylbenzylamine and 0.002 times the mass of hexamethylol melamine catalyst p-toluenesulfonic acid were added. The mixture was heated to 90°C, refluxed for 5 hours, cooled to 65°C, and the pH was adjusted to 7.5 with triethylamine to obtain benzylamine-modified melamine. S3. Under a nitrogen atmosphere, N-(2,4-difluorophenyl)-4-nitrobenzenesulfonamide and N,N-dimethylformamide were mixed at a mass ratio of 2:20 and stirred until homogeneous. Then, potassium carbonate (0.08 times the mass of N,N-dimethylformamide) and 4-fluoroaniline (0.05 times the mass of N,N-dimethylformamide) were added. The mixture was heated to 85°C and reacted for 18 hours. The temperature was then lowered to 4°C, and the mixture was extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrobenzenesulfonamide). Diamine; Under a nitrogen atmosphere, N,N-dimethylformamide and hexamethylol melamine were mixed at a mass ratio of 20:1.5, heated to 65°C, stirred and dissolved, and then N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyl diamine (1.3 times the mass of hexamethylol melamine) and formic acid (0.005 times the mass of hexamethylol melamine) were added as a catalyst. The mixture was heated to 90°C and refluxed for 4-8 hours. The precipitate was obtained by precipitating with ethanol, filtering, washing with ethanol 6 times, and drying in a vacuum oven at 70°C for 18 hours to obtain sulfonyl diamine modified melamine; S4. Mix benzylamine-modified melamine and sulfonyl diamine-modified melamine at a mass ratio of 1:2 to prepare a composite flame retardant; S5. By weight, place the filler and surface modifier in a mixer, heat to 135°C, mix at 1600 rpm for 4 min, cool to 110°C, add self-made antistatic agent, composite flame retardant, polypropylene, lubricant, dispersant, antioxidant and toughening agent, continue mixing for 3 min, heat to 165°C, continue mixing for 5 min, melt extrusion granulation to obtain antistatic and flame retardant functional masterbatch. Example 3

[0021] The raw materials of the antistatic and flame-retardant functional masterbatch in this embodiment are: 5 parts homemade antistatic agent, 3 parts composite flame retardant, 120 parts polypropylene, 320 parts filler calcium carbonate, 2 parts surface modifier polyethylene wax, 8 parts lubricant polyethylene wax, 3 parts dispersant calcium stearate, 0.2 parts antioxidant B215 and 8 parts toughening agent EVA. The preparation method of the antistatic and flame-retardant functional masterbatch in this embodiment is as follows: S1. Under a nitrogen atmosphere, hydroxyl-terminated polybutadiene and dichloromethane were mixed at a mass ratio of 1:2.2 and stirred until dissolved. Then, sodium hydroxide (0.32 times the mass of the hydroxyl-terminated polybutadiene) was added, and the reaction was continued for 30 min to activate the reaction. A 50% dichloromethane solution of 1-chloro-2,4-dinitrobenzene (0.4 times the mass of the hydroxyl-terminated polybutadiene) was added dropwise at a rate of 3 ml / min. The reaction was continued for 24 h. Finally, 4,4′,4″-triphenylmethane (1.2 times the mass of the hydroxyl-terminated polybutadiene) was added. Triisocyanate and stannous octoate catalyst (0.002 times the mass of hydroxyl-terminated polybutadiene) were stirred until homogeneous, allowed to stand to degas, and then transferred to an 80°C oven for curing for 12 hours to obtain a network crosslinked isocyanate. Under a nitrogen atmosphere, N-methylpyrrolidone and 2,2'-bis(trifluoromethyl)benzidine were mixed at a mass ratio of 25:8, heated to 32°C, stirred until dissolved, and then 4,4'-(hexafluoroisopropylidene) phthalic anhydride (0.18 times the mass of N-methylpyrrolidone) were added. The mixture was then heated to 42°C and reacted for 3 hours. h, add 0.1 times the mass of N-methylpyrrolidone to pyromellitic dianhydride, heat to 82℃, react for 70 min, then add N-methylpyrrolidone to adjust the solid content to 20%, to obtain copolymerized polyamic acid; under a nitrogen atmosphere, mix network crosslinked isocyanate, bicarboxyl-terminated polyethylene glycol and dichloromethane in a mass ratio of 1:2:30, stir to dissolve, then add 0.03 times the mass of network crosslinked isocyanate to 4-dimethylaminopyridine, place in an ice bath at 5℃, and add 0 times the mass of network crosslinked isocyanate to 4-dimethylaminopyridine. Dicyclohexylcarbodiimide was added at a concentration of 0.08 times and reacted for 2 hours. The mixture was then heated to room temperature and reacted for 24 hours. After filtration and precipitation with ethanol, the mixture was filtered again and mixed with copolymerized polyamic acid at a mass ratio of 3:10. The mixture was stirred at 400 rpm for 2 hours, heated to 82°C and reacted for 60 minutes, then heated to 122°C and reacted for 60 minutes, then heated to 182°C and reacted for 60 minutes, then heated to 252°C and reacted for 60 minutes, then heated to 302°C and reacted for 60 minutes. The mixture was then cooled to room temperature to obtain the self-made antistatic agent. S2. Methanol and o-hydroxybenzaldehyde were mixed at a mass ratio of 20:1.2, stirred until dissolved, and then cooled to 5°C in an ice bath. A 33% methylamine methanol solution (5.4 times the mass of o-hydroxybenzaldehyde) was added dropwise at a rate of 3 ml / min. The pH was adjusted to 6 with glacial acetic acid, and then sodium cyanoborohydride (0.6 times the mass of o-hydroxybenzaldehyde) was added. The mixture was heated to room temperature and reacted for 6 hours. Then, ice water (50 times the mass of o-hydroxybenzaldehyde) was added, and the pH was adjusted to 10 with sodium hydroxide. The mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The mixture was condensed and then subjected to silica gel column chromatography with petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain o-hydroxy-N-methylbenzylamine. Isopropanol and hexamethylol melamine were mixed at a mass ratio of 30:3, heated to 80°C, stirred until homogeneous, and then 1.3 times the mass of o-hydroxy-N-methylbenzylamine and 0.003 times the mass of hexamethylol melamine catalyst p-toluenesulfonic acid were added. The mixture was heated to 100°C, refluxed for 6 hours, cooled to 70°C, and the pH was adjusted to 8 with triethylamine to obtain benzylamine-modified melamine. S3. Under a nitrogen atmosphere, N-(2,4-difluorophenyl)-4-nitrobenzenesulfonamide and N,N-dimethylformamide were mixed at a mass ratio of 3:20 and stirred until homogeneous. Then, potassium carbonate (0.09 times the mass of N,N-dimethylformamide) and 4-fluoroaniline (0.06 times the mass of N,N-dimethylformamide) were added. The mixture was heated to 90°C and reacted for 24 h. The temperature was then lowered to 0–5°C, and the mixture was extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl). Sulfodiamine; Under a nitrogen atmosphere, N,N-dimethylformamide and hexamethylol melamine were mixed at a mass ratio of 20:2, heated to 70°C, stirred and dissolved, and then N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine (1.4 times the mass of hexamethylol melamine) and formic acid (0.002 times the mass of hexamethylol melamine) were added as a catalyst. The mixture was heated to 100°C and refluxed for 8 hours. The precipitate was obtained by precipitating with ethanol, filtering, washing with ethanol 8 times, and drying in a vacuum oven at 80°C for 24 hours to obtain sulfonyldiamine-modified melamine. S4. Mix benzylamine-modified melamine and sulfonyl diamine-modified melamine at a mass ratio of 1:3 to prepare a composite flame retardant; S5. By weight, place the filler and surface modifier in a mixer, heat to 150°C, mix at 1700 rpm for 5 min, cool to 115°C, add self-made antistatic agent, composite flame retardant, polypropylene, lubricant, dispersant, antioxidant and toughening agent, continue mixing for 4 min, heat to 170°C, continue mixing for 6 min, melt extrusion granulation to obtain antistatic and flame retardant functional masterbatch.

[0022] Comparative Example 1 The preparation method of Comparative Example 1 is the same as that of Example 2. The difference between this antistatic and flame-retardant functional masterbatch and Example 2 is that the self-made antistatic agent is prepared by reacting 4,4′,4″-triphenylmethane triisocyanate with bi-carboxyl-terminated polyethylene glycol, and then crosslinking it with copolymerized polyamic acid.

[0023] Comparative Example 2 The preparation method of Comparative Example 2 is the same as that of Example 2. The difference between this antistatic and flame-retardant functional masterbatch and Example 2 is that the self-made antistatic agent is obtained by crosslinking a network crosslinked isocyanate with a copolymerized polyamic acid.

[0024] Comparative Example 3 The preparation method of Comparative Example 3 is the same as that of Example 2. The difference between this antistatic and flame-retardant masterbatch and Example 2 is that the composite flame retardant is only benzylamine-modified melamine.

[0025] Comparative Example 4 The preparation method of Comparative Example 4 is the same as that of Example 2. The difference between this antistatic and flame-retardant masterbatch and Example 2 is that the composite flame retardant is only sulfonyl diamine modified melamine.

[0026] Comparative Example 5 The preparation method of Comparative Example 5 is the same as that of Example 2. The difference between this antistatic and flame-retardant masterbatch and Example 2 is that the composite flame retardant is only hexamethylol melamine.

[0027] Example of effect Table 1 below shows the performance test results of the antistatic and flame-retardant functional masterbatches prepared in the examples and comparative examples; Table 1

[0028] As can be seen from the performance data comparison in Table 1, the antistatic and flame-retardant functional masterbatch prepared by the present invention has excellent antistatic and flame-retardant properties. Comparison of experimental data from Examples 1, 2, and 3 and Comparative Examples 1 and 2 reveals that the self-made antistatic agent is prepared by reacting a network-crosslinked isocyanate with bi-carboxyl-terminated polyethylene glycol, followed by crosslinking with a copolymeric polyamic acid. The network-crosslinked isocyanate is prepared by reacting hydroxyl-terminated polybutadiene, 4,4′,4″-triphenylmethane triisocyanate, and 1-chloro-2,4-dinitrobenzene. The copolymeric polyamic acid is prepared by reacting 2,2'-bis(trifluoromethyl)benzidine, 4,4'-(hexafluoroisopropylidene)phthalic anhydride, and pyromellitic dianhydride. The reaction yields a network-crosslinked isocyanate whose hydroxyl groups react with bi-carboxyl-terminated polyethylene glycol. Simultaneously, polyethylene oxide is introduced onto the side chains, and the isocyanate groups further crosslink with a copolymerized polyamic acid, forming a high-molecular-weight permanent antistatic agent. This not only prevents the antistatic agent from migrating or precipitating too quickly to the surface, achieving long-lasting antistatic properties, but also forms a conductive water film, providing ion-conducting channels to rapidly dissipate static charge and further enhance antistatic properties. When co-extruded with a composite flame retardant, a crosslinked structure is formed in the masterbatch, synergistically enhancing flame retardant performance.

[0029] A comparison of the experimental data from Examples 1, 2, and 3 and Comparative Examples 3, 4, and 5 reveals that the composite flame retardant includes benzylamine-modified melamine and sulfonyldiamine-modified melamine. Benzylamine-modified melamine is prepared by reacting hexamethylol melamine with o-hydroxy-N-methylbenzylamine, while sulfonyldiamine-modified melamine is prepared by reacting hexamethylol melamine with N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine. The introduction of benzylamine side chains containing benzene rings and tertiary amine groups into the melamine structure not only enhances the compatibility of the flame retardant with the polymer matrix but also... Amine groups can promote char formation and capture free radicals during combustion. By grafting sulfonamide structures containing fluorine, nitro, and sulfonamides onto melamine rings, the introduction of fluorine can reduce the surface energy of the material and form a flame-retardant barrier. Nitro groups can decompose at high temperatures to produce nitrogen-containing flame-retardant gases. The introduced sulfonamides further enhance the thermal stability of the flame retardant. After the two modified melamines are combined, through synergistic effects, they can release inert gases in the gas phase to dilute the concentration of combustible gases and inhibit the combustion reaction, and promote the formation of a dense and stable char layer in the condensed phase to isolate heat and oxygen transfer, thereby giving the masterbatch excellent flame-retardant properties.

[0030] Obviously, the above embodiments are merely examples to clearly illustrate the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, these obvious variations or modifications derived from the spirit of the present invention are still within the protection scope of the present invention.

Claims

1. A masterbatch with antistatic and flame-retardant properties, characterized in that, The raw material components include the following parts by weight: 2-5 parts of self-made antistatic agent, 1-3 parts of composite flame retardant, 100-120 parts of polypropylene, 280-320 parts of filler, 1-2 parts of surface modifier, 6-8 parts of lubricant, 2-3 parts of dispersant, 0.1-0.2 parts of antioxidant and 4-8 parts of toughening agent; the self-made antistatic agent is prepared by reacting network crosslinked isocyanate with double-terminated carboxyl polyethylene glycol, and then crosslinking it with copolymerized polyamic acid.

2. The antistatic and flame-retardant functional masterbatch according to claim 1, characterized in that, The network cross-linked isocyanate is prepared by reacting hydroxyl-terminated polybutadiene, 4,4′,4″-triphenylmethane triisocyanate, and 1-chloro-2,4-dinitrobenzene; the copolymerized polyamic acid is prepared by reacting 2,2'-bis(trifluoromethyl)benzidine, 4,4'-(hexafluoroisopropylidene) phthalic anhydride, and pyromellitic dianhydride.

3. The antistatic and flame-retardant functional masterbatch according to claim 1, characterized in that, The composite flame retardant includes benzylamine-modified melamine and sulfonyldiamine-modified melamine; the benzylamine-modified melamine is prepared by reacting hexahydroxymethyl melamine with o-hydroxy-N-methylbenzylamine; the sulfonyldiamine-modified melamine is prepared by reacting hexahydroxymethyl melamine with N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine.

4. The antistatic and flame-retardant functional masterbatch according to claim 1, characterized in that, The filler is calcium carbonate; the surface modifier is polyethylene wax; the lubricant is polyethylene wax; the dispersant is calcium stearate; the antioxidant is B215; and the toughening agent is either POE or EVA.

5. The method for preparing an antistatic and flame-retardant functional masterbatch according to claim 1, characterized in that, The specific steps include the following: S1. Under a nitrogen atmosphere, cross-linked isocyanate, bi-carboxyl-terminated polyethylene glycol, and dichloromethane are dissolved by stirring at a mass ratio of 1:2:20-30. Then, 0.01-0.03 times the mass of the cross-linked isocyanate (4-dimethylaminopyridine) is added. The mixture is placed in an ice bath at 0-5°C. Next, 0.06-0.08 times the mass of the cross-linked isocyanate (dicyclohexylcarbodiimide) is added. The reaction is carried out for 1-2 hours, then heated to room temperature and reacted for 20-24 hours. The mixture is filtered and precipitated with ethanol. After vacuum filtration, it is combined with copolymers. Polyamic acid of type 1 was mixed at a mass ratio of 1~3:10, stirred at 200~400 rpm for 1~2 hours, heated to 80~82℃ and reacted for 50~60 minutes, heated to 120~122℃ and reacted for 50~60 minutes, heated to 180~182℃ and reacted for 50~60 minutes, heated to 250~252℃ and reacted for 50~60 minutes, heated to 300~302℃ and reacted for 50~60 minutes, and then cooled to room temperature to obtain a self-made antistatic agent. S2. Mix isopropanol and hexamethylol melamine at a mass ratio of 20-30:3, heat to 70-80℃, stir evenly, add o-hydroxy-N-methylbenzylamine at 1.2-1.3 times the mass of hexamethylol melamine, and p-toluenesulfonic acid catalyst at 0.001-0.003 times the mass of hexamethylol melamine, heat to 80-100℃, reflux for 4-6 hours, cool to 60-70℃, and adjust the pH to 7-8 with triethylamine to obtain benzylamine-modified melamine; S3. Under a nitrogen atmosphere, N,N-dimethylformamide and hexamethylol melamine are mixed at a mass ratio of 20:1~2, heated to 60~70℃, stirred and dissolved, and then N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyldiamine (1.2~1.4 times the mass of hexamethylol melamine) and formic acid (0.001~0.002 times the mass of hexamethylol melamine) are added as a catalyst. The mixture is heated to 80~100℃ and refluxed for 4~8 hours. The precipitate is obtained with ethanol, filtered, washed with ethanol 5~8 times, and dried in a vacuum oven at 60~80℃ for 12~24 hours to obtain sulfonyldiamine modified melamine. S4. Mix benzylamine-modified melamine and sulfonyl diamine-modified melamine to prepare a composite flame retardant; S5. By weight, place the filler and surface modifier in a mixer, heat to 120~150℃, mix at 1500~1700rpm for 3~5min, cool to 105~115℃, add self-made antistatic agent, composite flame retardant, polypropylene, lubricant, dispersant, antioxidant and toughening agent, continue mixing for 2~4min, heat to 160~170℃, continue mixing for 4~6min, melt extrusion granulation to obtain antistatic and flame retardant functional masterbatch.

6. The method for preparing an antistatic and flame-retardant functional masterbatch according to claim 5, characterized in that, In step S1 above, the preparation method of the network cross-linked isocyanate is as follows: Under a nitrogen atmosphere, hydroxyl-terminated polybutadiene and dichloromethane are mixed at a mass ratio of 1:2~2.2, stirred and dissolved, and then sodium hydroxide is added at a mass ratio of 0.3~0.32 times that of hydroxyl-terminated polybutadiene. The activation reaction is continued for 20~30 min. A dichloromethane solution of 1-chloro-2,4-dinitrobenzene with a mass fraction of 40~50% is added dropwise at a rate of 1~3 ml / min at a mass ratio of 0.3~0.4 times that of hydroxyl-terminated polybutadiene. The reaction is continued for 12~24 h. Then, 4,4′,4″-triphenylmethane triisocyanate at a mass ratio of 1~1.2 times that of hydroxyl-terminated polybutadiene and stannous octoate catalyst at a mass ratio of 0.001~0.002 times that of hydroxyl-terminated polybutadiene are added. After stirring evenly, the mixture is allowed to stand to remove bubbles and then transferred to an oven at 60~80℃ for curing for 6~12 h to obtain the network cross-linked isocyanate.

7. The method for preparing an antistatic and flame-retardant functional masterbatch according to claim 5, characterized in that, In step S1 above, the preparation method of the copolymer polyamic acid is as follows: Under a nitrogen atmosphere, N-methylpyrrolidone and 2,2'-bis(trifluoromethyl)benzidine are mixed at a mass ratio of 25:6~8, heated to 30~32℃, stirred and dissolved, then 0.16~0.18 times the mass of N-methylpyrrolidone of 4,4'-(hexafluoroisopropylidene) diaphthalic anhydride is added, heated to 40~42℃, and reacted for 2~3 hours. Then, 0.08~0.1 times the mass of N-methylpyrrolidone of pyromellitic dianhydride is added, heated to 80~82℃, and reacted for 50~70 minutes. Finally, N-methylpyrrolidone is added again, and the solid content is adjusted to 18~20% to obtain the copolymer polyamic acid.

8. The method for preparing an antistatic and flame-retardant functional masterbatch according to claim 5, characterized in that, In step S2 above, the preparation method of o-hydroxy-N-methylbenzylamine is as follows: Methanol and o-hydroxybenzaldehyde are mixed at a mass ratio of 20:1~1.2, stirred and dissolved, and then placed in an ice bath to cool to 0~5℃. A 33% methylamine methanol solution with a mass fraction of 5.2~5.4 times that of o-hydroxybenzaldehyde is added dropwise at a rate of 1~3 ml / min. The pH is adjusted to 5~6 with glacial acetic acid, and then sodium cyanoborohydride with a mass fraction of 0.4~0.6 times that of o-hydroxybenzaldehyde is added. The mixture is heated to room temperature and reacted for 4~6 h. Ice water with a mass fraction of 50 times that of o-hydroxybenzaldehyde is added, and the pH is adjusted to 9~10 with sodium hydroxide. The mixture is extracted with ethyl acetate, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure, and then subjected to silica gel column chromatography with petroleum ether and ethyl acetate in a volume ratio of 5:1 to obtain o-hydroxy-N-methylbenzylamine.

9. The method for preparing an antistatic and flame-retardant functional masterbatch according to claim 5, characterized in that, In step S3 above, the preparation method of N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyl diamine is as follows: Under a nitrogen atmosphere, N-(2,4-difluorophenyl)-4-nitrobenzenesulfonamide and N,N-dimethylformamide are mixed at a mass ratio of 1~3:

20. After stirring evenly, 0.07~0.09 times the mass of N,N-dimethylformamide in potassium carbonate and 0.04~0.06 times the mass of N,N-dimethylformamide in 4-fluoroaniline are added. The temperature is raised to 80~90℃ and reacted for 12~24h. The temperature is lowered to 0~5℃, extracted with ethyl acetate, washed with saturated brine, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain N-(4-fluorophenyl)-N'-(2-fluoro-4-nitrophenyl)sulfonyl diamine.

10. The method for preparing an antistatic and flame-retardant functional masterbatch according to claim 5, characterized in that, In step S4 above, the mass ratio of benzylamine-modified melamine to sulfonamide-modified melamine is 1:1~3.

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