Super-dispersed flame-retardant engineering plastic master batch and preparation method thereof

Abstract

The application discloses a kind of superdispersion flame-retardant engineering plastic master batch and preparation method thereof, it is related to functional plastic technical field, including functional master batch, the functional master batch includes the following components by weight parts: nylon 6 sheet 100 parts, modified carbon nanotube 0.5-8 parts, diethyl phosphinic acid ethyl aluminum 5-15 parts, flame retardant 5-15 parts, carbon forming agent 2-5 parts, epoxy silicon dioxide 0.5-5 parts, compatible agent 0.5-5 parts.The application introduces diethyl phosphinic acid ethyl aluminum and flame retardant, forms carbon layer on the material surface when plastic master batch burns, and the interaction between the molecular chains of plastic master batch is improved by Schiff base structure, realizes the double performance improvement of plastic master batch flame retardant and anti-dripping, solves the problem of fire spread caused by melt dripping.

Description

Technical Field

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

[0002] With the development of modern industry, people's requirements for material performance are increasing. Polyamide 6 (PA6), as a widely used engineering plastic, has excellent mechanical properties, wear resistance, chemical corrosion resistance, and good processing performance, and is widely used in automobiles, electronics, aerospace, and other fields. However, in actual production and application, PA6 is a flammable material, and it is prone to dripping during combustion.

[0003] When PA6 burns, it is accompanied by melting and dripping. These high-temperature liquid substances adhere to the surface of combustibles and may cause secondary combustion, leading to the spread of the fire. At the same time, the high volume resistivity of PA6 makes it easy to accumulate static electricity, increasing the risk of fire and explosion.

[0004] Patent CN114854194B discloses a flame-retardant plastic masterbatch and its preparation method. The above patent achieves good compatibility between raw materials, improves the compatibility between components, improves the product stability of the flame-retardant plastic masterbatch, and the flame-retardant components synergistically improve the flame-retardant effect.

[0005] The aforementioned patents reduced the interface difference between inorganic and organic raw materials and solved the problem of poor compatibility between flame retardants and polymers. However, there is still room for improvement in the anti-dripping performance of plastic masterbatches. This application prepares plastic masterbatches with both excellent anti-dripping performance and high flame retardant performance, solving the problem of secondary combustion caused by the dripping of engineering plastics.

[0006] Therefore, this application proposes a super-dispersed flame-retardant engineering plastic masterbatch that achieves both excellent anti-dripping properties and high flame-retardant properties, and its preparation method. Summary of the Invention

[0007] The purpose of this invention is to provide an ultra-dispersed flame-retardant engineering plastic masterbatch and its preparation method, so as to solve the technical problem of secondary combustion caused by the dripping of molten engineering plastics mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a super-dispersed flame-retardant engineering plastic masterbatch, comprising a functional masterbatch, wherein the functional masterbatch comprises the following components by weight: 100 parts of nylon 6 sheet, 0.5-8 parts of modified carbon nanotubes, 5-15 parts of diethylphosphine-modified ethyl aluminum phosphite, 5-15 parts of flame retardant, 2-5 parts of charring agent, 0.5-5 parts of epoxidized silica, and 0.5-5 parts of compatibilizer. The preparation method of the diethylphosphine-modified ethyl aluminum phosphite includes the following steps:

[0009] Aluminum sulfate was dissolved in deionized water to prepare a metal salt solution. The metal salt solution was heated to 50°C, and a mixture of diethylphosphoric acid and ethylphosphorous acid was slowly added dropwise to the metal salt solution. The mixture was stirred for 1 hour.

[0010] After cooling to room temperature, the product is filtered, washed, and dried. The dried product is then pulverized to obtain diethylphosphine-modified ethyl aluminum phosphite.

[0011] Preferably, the method for preparing the char-forming agent includes the following steps:

[0012] Enzymatically hydrolyzed lignin was dissolved in N,N-dimethylformamide, and then triglycidyl isocyanurate, aminotrimethylphosphonic acid, and benzoic acid were added sequentially. The mixture was then eluted with ethanol, dried, and pulverized to obtain a char-forming agent.

[0013] Preferably, the method for preparing the flame retardant includes the following steps:

[0014] Benzoguanidine and p-methoxybenzaldehyde were mixed and added to toluene, p-toluenesulfonic acid was added, the mixture was stirred evenly and heated to 110°C, and then refluxed to obtain the reactants.

[0015] The liquid portion of the reactants was filtered off using a vacuum filtration device to obtain a solid product. The solid product was washed with anhydrous ethanol and then dried in an oven at 50°C to obtain the flame retardant.

[0016] Preferably, the method for preparing the modified carbon nanotubes includes the following steps:

[0017] Carbon nanotubes were dispersed in a mixed solution of deionized water and ethanol, spirocyclic pentaerythritol diphosphate was added, and the mixture was dispersed using an ultrasonic disperser. The solution was heated to 80°C and stirred for 10 hours to obtain a suspension.

[0018] The suspension was filtered and washed, and the filtered product was placed in an oven and dried at 80°C for 12 hours. The dried product was then ground to obtain modified carbon nanotubes.

[0019] Preferably, the method for preparing the spirocyclic pentaerythritol diphosphate includes the following steps:

[0020] Phosphorus oxychloride and pentaerythritol were mixed and added to a reaction vessel, heated to 100°C and stirred, then filtered, washed and distilled under reduced pressure to obtain spirocyclic pentaerythritol dichloride phosphate.

[0021] Spirocyclopentaerythritol dichloride and triethylamine were dissolved in acetonitrile, and a mixed solution of 3-aminopropyltriethoxysilane and acetonitrile was added dropwise. The mixture was stirred at 40°C for 10 h, filtered, and distilled under reduced pressure to obtain spirocyclopentaerythritol dichloride.

[0022] Preferably, the method for preparing the compatibilizer includes the following steps:

[0023] Epichlorohydrin was slowly added dropwise to a hexamethylenediamine solution and reacted at 70°C for 2 hours. The mixture was then dehydrated under reduced pressure and dried to obtain a polar polymer. The polar polymer and maleic anhydride-grafted polypropylene were added to xylene and reacted at 120°C for 8 hours. The mixture was then washed with ethanol, filtered, and dried to obtain an intermediate product.

[0024] The intermediate product was added to xylene, heated to 100 °C, and then modified graphene oxide and butylammonium bromide were added sequentially. The mixture was reacted at 120 °C for 8 hours, and then filtered, dried, and ground to obtain the compatibilizer.

[0025] Preferably, the epoxidized silica is prepared by modifying silica with 3-glycidyloxypropyltrimethoxysilane and n-octyltriethoxysilane.

[0026] Preferably, the modified graphene oxide is prepared by modifying graphene oxide with 2,3-epoxypropyltrimethylammonium chloride.

[0027] Preferably, the preparation method includes the following steps:

[0028] S1. Using a high-speed mixer, Nylon 6 sheet, modified carbon nanotubes, diethylphosphine-modified aluminum ethyl phosphite, flame retardant, charring agent, epoxidized silica, and compatibilizer are mixed to obtain a mixture.

[0029] S2. Feed the mixture into the feed port of a twin-screw extruder. Set the extruder temperature to 210-250℃. After water-cooled granulation, place the granulated particles into an oven and dry them at 120℃ for 10 hours to obtain functional masterbatch.

[0030] Preferably, the preparation method further includes the following steps:

[0031] S11. Place the nylon 6 sheet in an oven and dry it at 120°C for 10 hours.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. This invention introduces diethylphosphine-modified aluminum ethyl phosphite and a flame retardant to form a char layer on the surface of the plastic masterbatch during combustion. The Schiff base structure enhances the interaction force between the molecular chains of the plastic masterbatch, thereby achieving a dual improvement in the flame retardant and anti-dripping properties of the plastic masterbatch and solving the problem of fire spread caused by dripping.

[0034] 2. This invention introduces a lignin-based char-forming agent, which works together with phosphorus-containing diethylphosphine-modified ethyl aluminum phosphite and nitrogen- and phosphorus-containing flame retardants to form a highly efficient flame retardant system containing carbon, nitrogen, and phosphorus elements, thereby further improving the flame retardant effect of plastic masterbatch and enhancing the overall flame retardant performance of functional masterbatch.

[0035] 3. This invention introduces modified carbon nanotubes to form a conductive network in the plastic masterbatch, thereby improving the antistatic properties of the functional masterbatch, promoting the rapid release of charge, effectively suppressing the accumulation and discharge of static electricity in the plastic masterbatch, solving the problem of sparks caused by static electricity igniting itself or surrounding combustibles, and ensuring the safety of the plastic masterbatch production and use process.

[0036] 4. This invention reduces the interfacial tension between components by introducing a compatibilizer containing graphene oxide nanosheets, enhances the interaction force between components of the functional masterbatch, and improves the compatibility and stability between components of the plastic masterbatch. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the functional masterbatch preparation process of the present invention;

[0038] Figure 2 This is a schematic diagram of the preparation process of diethylphosphine-modified aluminum ethyl phosphite according to the present invention;

[0039] Figure 3 This is a schematic diagram of the carbon-forming agent preparation process of the present invention;

[0040] Figure 4 This is a schematic diagram of the flame retardant preparation process of the present invention;

[0041] Figure 5 This is a schematic diagram of the preparation process of the modified carbon nanotubes of the present invention;

[0042] Figure 6 This is a schematic diagram of the preparation process of spirocyclic pentaerythritol dichlorobisphosphate according to the present invention;

[0043] Figure 7 This is a schematic diagram of the preparation process of the spirocyclic pentaerythritol diphosphate of the present invention;

[0044] Figure 8 This is a schematic diagram of the compatibilizer preparation process of the present invention. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0046] Example 1, please refer to Figure 1 and Figure 2 A method for preparing ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0047] Aluminum sulfate was dissolved in deionized water to prepare a metal salt solution. The metal salt solution was heated to 50°C. A mixture of diethylphosphine and ethylphosphite was slowly added dropwise to the metal salt solution. The mixture was stirred for 1 hour and cooled to room temperature. The solution was then filtered, washed, and dried. The dried product was pulverized to obtain aluminum diethylphosphine-phosphate.

[0048] 100 parts of nylon 6 sheet, 8 parts of modified carbon nanotubes, 15 parts of diethylphosphine-modified aluminum ethyl phosphite, 15 parts of flame retardant, 5 parts of charring agent, 5 parts of epoxy silica and 5 parts of compatibilizer were mixed using a high-speed mixer to obtain a mixture.

[0049] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0050] Furthermore, as a mixed salt, diethylphosphine-aluminum ethyl phosphite combines with both diethylphosphite and ethyl phosphite ions during crystal formation, forming a crystal structure with hydrophobic ends. This makes it easier for diethylphosphine-aluminum ethyl phosphite to produce small crystals in the reaction system, rather than growing into large crystals. This improves the dispersibility and stability of diethylphosphine-aluminum ethyl phosphite when blended with other materials, thus enhancing the dispersion effect of the material. In addition, diethylphosphine-aluminum ethyl phosphite has excellent flame retardant properties, thereby improving the thermal stability of the functional masterbatch. It can promote the formation of an expanded char layer in the polymer during combustion, effectively blocking oxygen and heat transfer, slowing down the combustion rate, and preventing further combustion. When the functional masterbatch burns, diethylphosphine-aluminum ethyl phosphite decomposes upon heating to produce water vapor and aluminum phosphate, which can effectively absorb heat in the combustion zone and dilute combustible gases, preventing further flame spread. Moreover, when diethylphosphine-aluminum ethyl phosphite is mixed with flame retardants, charring agents, and other components, it can exert a synergistic flame retardant effect, further enhancing the flame retardant performance of the material.

[0051] Example 2, please refer to Figure 1 and Figure 3 A method for preparing ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0052] Enzymatically hydrolyzed lignin was dissolved in N,N-dimethylformamide, and then triglycidyl isocyanurate, aminotrimethylphosphonic acid, and benzoic acid were added sequentially. The mixture was then eluted with ethanol, dried, and pulverized to obtain a char-forming agent.

[0053] 100 parts of nylon 6 sheet, 6 parts of modified carbon nanotubes, 12 parts of diethylphosphine-modified aluminum ethyl phosphite, 12 parts of flame retardant, 4 parts of charring agent, 4 parts of epoxy silica and 4 parts of compatibilizer were mixed using a high-speed mixer to obtain a mixture.

[0054] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0055] Furthermore, a lignin-based charring agent is prepared by enzymatic hydrolysis of lignin. The aromatic ring structure in the lignin molecule allows lignin to decompose under high temperature conditions to produce a stable char layer. This forms a dense char layer during combustion, which prevents heat transfer and blocks oxygen, slowing down the combustion process. Thus, the presence of the char layer reduces the combustion rate of the functional masterbatch during combustion, preventing the spread of fire and improving the flame retardant performance of the functional masterbatch. The lignin-based charring agent provides a carbon source for the flame retardant system of the functional masterbatch. When it works together with phosphorus-containing diethylphosphine-aluminum ethyl phosphite and nitrogen- and phosphorus-containing flame retardants, carbon, nitrogen, and phosphorus elements work synergistically to form a highly efficient flame retardant system. The decomposition of diethylphosphine-aluminum ethyl phosphite produces phosphate structures, providing an acid and gas source for the flame retardant process, while the lignin-based charring agent provides a carbon source, thereby further improving the flame retardant effect and enhancing the overall flame retardant performance of the functional masterbatch.

[0056] Example 3, please refer to Figure 1 and Figure 4 A method for preparing ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0057] Benzoguanidine and p-methoxybenzaldehyde were mixed and added to toluene, p-toluenesulfonic acid was added, the mixture was stirred evenly and heated to 110°C, and then refluxed to obtain the reactants. The liquid portion of the reactants was filtered off using a vacuum filter to obtain the solid product. The solid product was washed with anhydrous ethanol and then placed in an oven at 50°C for drying to obtain the flame retardant.

[0058] The following mixtures were prepared by mixing 100 parts of nylon 6 sheet, 5 parts of modified carbon nanotubes, 10 parts of diethylphosphine-modified aluminum ethyl phosphite, 10 parts of flame retardant, 3 parts of charring agent, 3 parts of epoxy silica and 3 parts of compatibilizer using a high-speed mixer to obtain a mixture.

[0059] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0060] Furthermore, the flame retardant is a triazine ring and Schiff base structure. The triazine ring structure expands into char during combustion, forming a dense char layer on the material surface. This effectively isolates the transfer of heat, oxygen, and flammable gases, slowing the combustion rate and improving the flame retardant performance of the functional masterbatch. The triazine ring structure decomposes upon heating, releasing water vapor, carbon dioxide, and other gases. These gases cause the functional masterbatch to expand, forming a porous char protective layer that further slows the combustion process. Simultaneously, the Schiff base structure can... An irreversible chemical cross-linking reaction occurs, forming a stable cross-linking network. The cross-linking effect increases the interaction force between the functional masterbatch molecular chains, making the functional masterbatch less prone to melting and dripping during combustion. This prevents the spread of fire caused by molten droplets during combustion, thereby improving the anti-dripping performance of the functional masterbatch. The synergistic effect of the flame retardant, charring agent, and diethylphosphine-modified ethyl aluminum phosphite enables the functional masterbatch to possess both excellent flame retardant and anti-dripping properties, achieving a dual improvement in the flame retardant and anti-dripping performance of the functional masterbatch.

[0061] Example 4, please refer to Figure 1 , Figure 5 , Figure 6 and Figure 7 A method for preparing ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0062] Phosphorus oxychloride and pentaerythritol were mixed and added to a reaction vessel, heated to 100°C and stirred. After filtration, washing and vacuum distillation, spirocyclic pentaerythritol diphosphate dichloroester was obtained. Spirocyclic pentaerythritol diphosphate dichloroester and triethylamine were dissolved in acetonitrile, and a mixed solution of 3-aminopropyltriethoxysilane and acetonitrile was added dropwise. The mixture was stirred at 40°C for 10 h, and after filtration and vacuum distillation, spirocyclic pentaerythritol diphosphate was obtained.

[0063] Carbon nanotubes were dispersed in a mixed solution of deionized water and ethanol, and spirocyclic pentaerythritol diphosphate was added. The mixture was dispersed using an ultrasonic disperser, heated to 80°C, and stirred for 10 hours to obtain a suspension. The suspension was filtered and washed, and the filtered product was placed in an oven and dried at 80°C for 12 hours. The dried product was then ground to obtain modified carbon nanotubes.

[0064] The following mixture was prepared by mixing 100 parts of nylon 6 sheet, 4 parts of modified carbon nanotubes, 8 parts of diethylphosphine-modified aluminum ethyl phosphite, 8 parts of flame retardant, 2 parts of charring agent, 2 parts of epoxy silica and 2 parts of compatibilizer using a high-speed mixer to obtain a mixture.

[0065] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0066] Furthermore, by grafting carbon nanotubes with spirocyclic pentaerythritol diphosphate, the compatibility of the modified carbon nanotubes with other components of the functional masterbatch is improved, enhancing the dispersibility of the modified carbon nanotubes within the functional masterbatch. This dispersion of the modified carbon nanotubes forms a conductive network within the functional masterbatch, reducing its resistivity and improving its antistatic properties. This effectively suppresses the accumulation and discharge of static electricity, preventing the generation of sparks due to the inability to promptly transfer the charge generated during friction. It also prevents the accumulation of charge on the surface of the functional masterbatch from breaking down the air insulation, thus solving the problem of static sparks igniting itself or surrounding combustibles, reducing the occurrence of fires, and addressing the issue of PA6 easily accumulating static electricity. This effectively reduces the surface resistivity of the material, decreases the accumulation and discharge of static electricity, and improves safety during use. In addition, the phosphorus element within the spirocyclic pentaerythritol diphosphate molecule participates in the formation of a stable char layer during combustion, thereby slowing down the combustion rate of the functional masterbatch and improving its flame retardant properties.

[0067] Example 5, please refer to Figure 1 and Figure 8 A method for preparing ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0068] Epichlorohydrin was slowly added dropwise to a hexamethylenediamine solution and reacted at 70°C for 2 hours. The mixture was then dehydrated under reduced pressure and dried to obtain a polar polymer. The polar polymer and maleic anhydride-grafted polypropylene were added to xylene and reacted at 120°C for 8 hours. The mixture was then washed with ethanol, filtered, and dried to obtain an intermediate product. This intermediate product was added to xylene, and the temperature was raised to 100°C. Modified graphene oxide and butylammonium bromide were added sequentially, and the mixture was reacted at 120°C for 8 hours. The mixture was then filtered, dried, and ground to obtain a compatibilizer.

[0069] The following mixture was prepared by mixing 100 parts of nylon 6 sheet, 2 parts of modified carbon nanotubes, 6 parts of diethylphosphine-modified aluminum ethyl phosphite, 6 parts of flame retardant, 1 part of charring agent, 1 part of epoxy silica and 1 part of compatibilizer using a high-speed mixer to obtain a mixture.

[0070] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0071] Furthermore, by introducing a composite compatibilizer, the interaction forces between the components of the functional masterbatch are enhanced, thereby improving the compatibility between the components of the functional masterbatch, improving the dispersion of components such as carbon nanotubes, flame retardants, and charring agents in the matrix nylon 6 sheet, and improving the interfacial bonding force between each component and the matrix nylon 6 sheet. The polymer chains in the composite compatibilizer can entangle with the polymer chains in the functional masterbatch matrix to form a tight network structure, thereby enhancing the interaction forces between the components of the functional masterbatch and improving the compatibility and stability of the material. By introducing a compatibilizer containing graphene oxide nanosheets, the interfacial tension between the components is reduced, thereby enabling the components to be uniformly dispersed. At the same time, the nanosheets have a high specific surface area and surface energy, thus generating a strong interaction with the polymer chains in the matrix nylon 6 sheet.

[0072] Example 6, please refer to Figure 1 A method for preparing ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0073] Aluminum sulfate was dissolved in deionized water to prepare a metal salt solution. The metal salt solution was heated to 50°C. A mixture of diethylphosphine and ethylphosphite was slowly added dropwise to the metal salt solution. The mixture was stirred for 1 hour and cooled to room temperature. The solution was then filtered, washed, and dried. The dried product was pulverized to obtain aluminum diethylphosphine-phosphate.

[0074] The following mixtures were prepared by mixing 100 parts of nylon 6 sheet, 0.5 parts of modified carbon nanotubes, 5 parts of diethylphosphine-modified ethyl aluminum phosphite, 5 parts of flame retardant, 0.5 parts of charring agent, 0.5 parts of epoxidized silica, and 0.5 parts of compatibilizer using a high-speed mixer to obtain a mixture.

[0075] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0076] Furthermore, the epoxy and alkoxy functional groups are introduced into the epoxidized silica, which allows the functional groups to interact with the functional groups in other components such as nylon 6 sheets, flame retardants, and charring agents. This improves the compatibility between functional masterbatches and enhances the dispersion uniformity of each component in the functional masterbatch. The modified nano-silica has good wettability and dispersibility, thus effectively filling the interfacial regions between the components.

[0077] Comparative Example 1: A method for preparing an ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0078] 100 parts of nylon 6 sheet, 8 parts of modified carbon nanotubes, 15 parts of flame retardant, 5 parts of charring agent, 5 parts of epoxidized silica and 5 parts of compatibilizer were mixed using a high-speed mixer to obtain a mixture.

[0079] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0080] Comparative Example 2: A method for preparing an ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0081] 100 parts of nylon 6 sheet, 8 parts of modified carbon nanotubes, 15 parts of diethylphosphine-modified aluminum ethyl phosphite, 15 parts of flame retardant, 5 parts of epoxy silica and 5 parts of compatibilizer were mixed using a high-speed mixer to obtain a mixture.

[0082] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0083] Comparative Example 3: A method for preparing an ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0084] 100 parts of nylon 6 sheet, 8 parts of modified carbon nanotubes, 15 parts of diethylphosphine-modified aluminum ethyl phosphite, 5 parts of carbon-forming agent, 5 parts of epoxy silica and 5 parts of compatibilizer were mixed using a high-speed mixer to obtain a mixture.

[0085] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0086] Comparative Example 4

[0087] A method for preparing ultra-dispersed flame-retardant engineering plastic masterbatch, the method comprising the following steps:

[0088] Phosphorus oxychloride and pentaerythritol were mixed and added to a reaction vessel, heated to 100°C and stirred. After filtration, washing and vacuum distillation, spirocyclic pentaerythritol diphosphate dichloroester was obtained. Spirocyclic pentaerythritol diphosphate dichloroester and triethylamine were dissolved in acetonitrile, and a mixed solution of 3-aminopropyltriethoxysilane and acetonitrile was added dropwise. The mixture was stirred at 40°C for 10 h, and after filtration and vacuum distillation, spirocyclic pentaerythritol diphosphate was obtained.

[0089] Carbon nanotubes were dispersed in a mixed solution of deionized water and ethanol, and spirocyclic pentaerythritol diphosphate was added. The mixture was dispersed using an ultrasonic disperser, heated to 80°C, and stirred for 10 hours to obtain a suspension. The suspension was filtered and washed, and the filtered product was placed in an oven and dried at 80°C for 12 hours. The dried product was then ground to obtain modified carbon nanotubes.

[0090] 100 parts of nylon 6 sheet, 0.5 parts of modified carbon nanotubes, 15 parts of diethylphosphine-modified aluminum ethyl phosphite, 5 parts of carbonizing agent, 5 parts of epoxy silica and 5 parts of compatibilizer were mixed using a high-speed mixer to obtain a mixture.

[0091] The mixture is fed from the feed port of a twin-screw extruder, the extruder temperature is set to 210-250℃, and after water cooling and granulation, the granulated particles are placed in an oven and dried at 120℃ for 10 hours to obtain functional masterbatch.

[0092] Performance testing

[0093] Test 1: Thermal stability test: Weigh 5 mg of the samples prepared in Examples 1-6 and Comparative Examples 1-3, place them in a thermogravimetric analyzer, and heat them to 800 °C at a rate of 10 °C / min under a nitrogen atmosphere. Record the initial decomposition temperature T. 5% ;

[0094] Test 2 Limiting Oxygen Index Test: The samples prepared in Examples 1-6 and Comparative Examples 1-3 were prepared using a tablet press and a cutter. The standard size of the test strip was 3.2mm × 6.5mm × 7mm. The limiting oxygen index was tested according to GB / T 2406.2—2009, and the LOI value was recorded.

[0095] Test 3 Vertical Burning Test: The samples prepared in Examples 1-6 and Comparative Examples 1-3 were prepared using a tablet press and a cutter. The standard test strip was 3mm×13mm×100mm. The test was conducted according to GB / T 2408—2008 standard, and the burning conditions were recorded.

[0096] Test 4: Volume resistivity test: The samples prepared in Examples 1-6 and Comparative Examples 1-3 were tested according to standard GB1410-2006, and the volume resistivity was recorded.

[0097] Table 1 Test results of sample performance testing

[0098] Example <![CDATA[T 5% (℃)]]> LOI (%) Volume resistivity (Ω·m) Example 1 389.74 31.4 <![CDATA[6.32×10 8 ]]> Example 2 370.13 30.2 <![CDATA[5.56×10 9 ]]> Example 3 359.82 29.1 <![CDATA[3.46×10 10 ]]> Example 4 351.27 27.9 <![CDATA[9.13×10 12 ]]> Example 5 348.86 26.5 <![CDATA[5.85×10 13 ]]> Example 6 336.27 24.6 <![CDATA[4.26×10 14 ]]> Comparative Example 1 381.54 30.4 <![CDATA[8.93×10 8 ]]> Comparative Example 2 378.54 29.8 <![CDATA[9.19×10 8 ]]> Comparative Example 3 372.46 29.4 <![CDATA[9.85×10 8 ]]> Comparative Example 4 384.15 30.7 <![CDATA[6.54×10 14 ]]>

[0099] Table 2. Test results of vertical combustion test of samples

[0100] Example First ignition combustion time (s) Second ignition combustion time (s) Molten droplet condition UL-94 Example 1 0 0 few V-0 Example 2 0 2 few V-0 Example 3 3 5 less V-1 Example 4 5 11 More V-1 Example 5 6 14 More V-1 Example 6 8 16 many V-2 Comparative Example 1 0 1 few V-0 Comparative Example 2 1 2 few V-0 Comparative Example 3 1 2 few V-0

[0101] Working principle: Diethylphosphine-modified aluminum ethyl phosphite produces small crystals in the reaction system, thereby improving the dispersibility and stability of the components of the functional masterbatch when blended, improving the dispersion effect of the material. Modified carbon nanotubes improve the antistatic properties of the functional masterbatch, while also showing good compatibility with other components of the functional masterbatch.

[0102] When the functional masterbatch burns, the diethylphosphine-modified aluminum ethyl phosphite, lignin-based charring agent, and flame retardant decompose upon heating, diluting the combustible gas, preventing the spread of fire, and forming a carbon layer to prevent heat transfer and isolate oxygen, thus slowing down the combustion process. The flame retardant with triazine ring and Schiff base structure makes it less likely for the functional masterbatch to produce drippings during combustion, thereby improving the flame retardancy and anti-drip properties of the functional masterbatch.

[0103] The molecular chains in the composite compatibilizer can form a network structure with the molecular chains in the functional masterbatch matrix, enhancing the interaction between the components of the functional masterbatch and improving the compatibility and stability of the material. Modified carbon nanotubes form a conductive network in the functional masterbatch, preventing sparks generated by static electricity from igniting themselves or surrounding combustibles.

[0104] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A super-dispersed flame-retardant engineering plastic masterbatch, characterized in that: The product includes a functional masterbatch, which comprises the following components by weight: 100 parts nylon 6 sheet, 0.5-8 parts modified carbon nanotubes, 5-15 parts diethylphosphine-modified ethyl aluminum phosphite, 5-15 parts flame retardant, 2-5 parts charring agent, 0.5-5 parts epoxidized silica, and 0.5-5 parts compatibilizer. The preparation method of the diethylphosphine-modified ethyl aluminum phosphite includes the following steps: Aluminum sulfate was dissolved in deionized water to prepare a metal salt solution. The metal salt solution was heated to 50°C, and a mixture of diethylphosphoric acid and ethylphosphorous acid was slowly added dropwise to the metal salt solution. The mixture was stirred for 1 hour. After cooling to room temperature, the product is filtered, washed, and dried. The dried product is then pulverized to obtain diethylphosphine-modified ethyl aluminum phosphite.

2. The ultra-dispersed flame-retardant engineering plastic masterbatch according to claim 1, characterized in that: The method for preparing the char-forming agent includes the following steps: Enzymatically hydrolyzed lignin was dissolved in N,N-dimethylformamide, and then triglycidyl isocyanurate, aminotrimethylphosphonic acid, and benzoic acid were added sequentially. The mixture was then eluted with ethanol, dried, and pulverized to obtain a char-forming agent.

3. The ultra-dispersed flame-retardant engineering plastic masterbatch according to claim 1, characterized in that: The method for preparing the flame retardant includes the following steps: Benzoguanidine and p-methoxybenzaldehyde were mixed and added to toluene, p-toluenesulfonic acid was added, the mixture was stirred evenly and heated to 110°C, and then refluxed to obtain the reactants. The liquid portion of the reactants was filtered off using a vacuum filtration device to obtain a solid product. The solid product was washed with anhydrous ethanol and then dried in an oven at 50°C to obtain the flame retardant.

4. The ultra-dispersed flame-retardant engineering plastic masterbatch according to claim 1, characterized in that: The method for preparing the modified carbon nanotubes includes the following steps: Carbon nanotubes were dispersed in a mixed solution of deionized water and ethanol, spirocyclic pentaerythritol diphosphate was added, and the mixture was dispersed using an ultrasonic disperser. The solution was heated to 80°C and stirred for 10 hours to obtain a suspension. The suspension was filtered and washed, and the filtered product was placed in an oven and dried at 80°C for 12 hours. The dried product was then ground to obtain modified carbon nanotubes.

5. The ultra-dispersed flame-retardant engineering plastic masterbatch according to claim 4, characterized in that: The method for preparing the spirocyclic pentaerythritol diphosphate includes the following steps: Phosphorus oxychloride and pentaerythritol were mixed and added to a reaction vessel, heated to 100°C and stirred, then filtered, washed and distilled under reduced pressure to obtain spirocyclic pentaerythritol dichloride phosphate. Spirocyclopentaerythritol dichloride and triethylamine were dissolved in acetonitrile, and a mixed solution of 3-aminopropyltriethoxysilane and acetonitrile was added dropwise. The mixture was stirred at 40°C for 10 h, filtered, and distilled under reduced pressure to obtain spirocyclopentaerythritol dichloride.

6. The ultra-dispersed flame-retardant engineering plastic masterbatch according to claim 1, characterized in that: The method for preparing the compatibilizer includes the following steps: Epichlorohydrin was slowly added dropwise to a hexamethylenediamine solution and reacted at 70°C for 2 hours. The mixture was then dehydrated under reduced pressure and dried to obtain a polar polymer. The polar polymer and maleic anhydride-grafted polypropylene were added to xylene and reacted at 120°C for 8 hours. The mixture was then washed with ethanol, filtered, and dried to obtain an intermediate product. The intermediate product was added to xylene, heated to 100 °C, and then modified graphene oxide and butylammonium bromide were added sequentially. The mixture was reacted at 120 °C for 8 hours, and then filtered, dried, and ground to obtain the compatibilizer.

7. The ultra-dispersed flame-retardant engineering plastic masterbatch according to claim 1, characterized in that: The epoxidized silica was prepared by modifying silica with 3-glycidyloxypropyltrimethoxysilane and n-octyltriethoxysilane.

8. The ultra-dispersed flame-retardant engineering plastic masterbatch according to claim 6, characterized in that: The modified graphene oxide was prepared by modifying graphene oxide with 2,3-epoxypropyltrimethylammonium chloride.

9. A method for preparing an ultra-dispersed flame-retardant engineering plastic masterbatch, applicable to the ultra-dispersed flame-retardant engineering plastic masterbatch according to any one of claims 1-8, characterized in that: The preparation method includes the following steps: S1. Using a high-speed mixer, Nylon 6 sheet, modified carbon nanotubes, diethylphosphine-modified aluminum ethyl phosphite, flame retardant, charring agent, epoxidized silica, and compatibilizer are mixed to obtain a mixture. S2. Feed the mixture into the feed port of a twin-screw extruder. Set the extruder temperature to 210-250℃. After water-cooled granulation, place the granulated particles into an oven and dry them at 120℃ for 10 hours to obtain functional masterbatch.

10. The method for preparing a super-dispersed flame-retardant engineering plastic masterbatch according to claim 9, characterized in that: The preparation method further includes the following steps: S11. Place the nylon 6 sheet in an oven and dry it at 120°C for 10 hours.

Images