Antistatic nylon material and preparation method thereof

Abstract

The invention relates to the technical field of nylon materials, in particular to an antistatic nylon material and a preparation method thereof. The antistatic nylon material comprises the following components in parts by weight: 85-90 parts of PA6 and 10-15 parts of a modified carbon black composite material, the modified carbon black composite material is formed by compounding lignin nanoparticles, carbon black impregnated and modified by sulfonated lignin and a silane coupling agent. According to the invention, the specific modified carbon black composite material is added into the PA6 resin, no additional dispersing aid needs to be added, the antistatic nylon material with excellent mechanical property, antistatic property, flame retardant property and water absorption resistance can be obtained, and the technical problem that the mechanical property of the resin can be influenced by adding an antistatic agent in the prior art is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nylon material, in particular to an antistatic nylon material and a preparation method thereof. BACKGROUND

[0002] Polyamide (PA, commonly known as nylon) is a kind of plastic with excellent comprehensive performance, and has good mechanical properties, wear resistance and processing performance, and is widely used in the fields of textiles, electronics, automobiles and the like.

[0003] Nylon 6 is one of the main varieties of polyamide, and the molecules of nylon 6 are combined by covalent bond, and the polar groups in the main chain structure are less, so the surface resistance of nylon 6 is relatively large, reaching 10 13 -10 14 Ω, and the conductivity is poor. When it is in contact or friction with the surface of other substances or materials, a large amount of static electricity is easily accumulated, which may cause dust absorption, breakdown of electronic devices, integrated circuit damage, discharge and the like, and even fire, explosion and other dangerous accidents, which has a great adverse effect on industrial production and daily life.

[0004] In order to reduce the harm of static electricity, an antistatic agent is usually directly coated on the surface of the material or the antistatic agent is added into the polyamide resin for blending, the former coating method has poor durability, and the latter blending method is prone to the problem of poor dispersion effect, which leads to the decrease of mechanical properties of the material. SUMMARY

[0005] In order to solve at least one aspect of the above problems, the present application provides an antistatic nylon material and a preparation method thereof, by adding a specific modified carbon black composite material in PA6 resin, without additional dispersion aids, the antistatic performance and flame retardant performance of the material are further improved while the mechanical properties are ensured, and the water absorption performance of the material is reduced.

[0006] In a first aspect, the present application provides an antistatic nylon material, comprising the following components by weight: PA6 85-90 parts, modified carbon black composite material 10-15 parts; the modified carbon black composite material is composed of lignin nanoparticles, carbon black modified by impregnating sulfonated lignin and silane coupling agent.

[0007] The present application utilizes carbon black to provide conductive paths, and lignin nanoparticles to enhance flame retardation and mechanical properties, wherein the sulfonated lignin can coat the carbon black to a certain extent, and the silane coupling agent can not only improve the dispersion effect of carbon black in PA6 resin, but also appropriately reduce the water absorption of the polar groups brought by the lignin nanoparticles and the sulfonated lignin; the combination of lignin nanoparticles, sulfonated lignin impregnated modified carbon black and silane coupling agent can avoid the defects of single filler, and further improve the dispersibility and interface bonding effect of the modified carbon black composite material and PA6 resin, so that the antistatic nylon material obtained has excellent mechanical properties, antistatic properties, flame retardation and water absorption resistance.

[0008] Optionally, the preparation method of the modified carbon black composite material comprises the following steps: Preparation of lignin nanoparticles: lignin is put into an alcohol aqueous solution of sodium hydroxide, and processing aids are supplemented and uniformly mixed, and then the lignin filtrate is obtained by filtering after heating and degradation treatment, and the system is slowly neutralized to pH 2-3 by adding hydrochloric acid, and the lignin nanoparticle-containing suspension I is obtained; Sulfonated lignin impregnated modified carbon black: sulfonated lignin is dissolved in water to form a sulfonated lignin aqueous solution, carbon black is put into the sulfonated lignin aqueous solution, and after ultrasonic dispersion and mixing, the impregnated treatment is carried out for 8-12h, and the suspension II containing sulfonated lignin impregnated modified carbon black is obtained; Preparation of silane coupling agent hydrolysate: the silane coupling agent is mixed with water, and hydrolysis treatment is carried out at 60-80℃ for 1-2h, and the silane coupling agent hydrolysate is obtained; Harvesting of the composite material: the suspension II is slowly added to the suspension I, and then the silane coupling agent hydrolysate is added after mixing, and shear emulsification treatment is carried out for 1-2h, and then the filter residue is dried at low temperature after filtration, and then the temperature is raised to 250-350℃ under the protection of inert gas for 5-10min, and the modified carbon black composite material is obtained.

[0009] The present application realizes the nanocrystallization of lignin by adopting the method of "alkali degradation + acid precipitation", which is simple in operation and controllable in process, and the addition of processing aids is used to inhibit side reactions, so as to ensure the stability of the nanoparticles; the sulfonated lignin is easily dissolved in water, and it is used in the form of aqueous solution to cooperate with the treatment mode of "ultrasonic + impregnation", which can better promote the sulfonated lignin to coat the carbon black and improve the hydrophilicity and dispersibility of the carbon black; the alkoxy group (-OR) of the silane coupling agent reacts with water to generate unstable silanol group (-SiOH) and corresponding alcohol (ROH), and the silanol group (-SiOH) is easy to form a covalent bond with the hydroxyl group on the surface of the carbon black, and then the composite is realized. The whole composite process is carried out in water, which is helpful for the full contact of the reactants and the participation in the reaction, and has better composite effect.

[0010] In the process of compounding, the sulfonic acid groups in the sulfonated lignin are protonated to a certain extent in the acidic system to form -SO3H2 + Agglomeration is easy to occur, so the present application slowly adds the second suspension (containing sulfonated lignin impregnated modified carbon black) to the first suspension (containing lignin nanoparticles) to gradually increase the pH of the first suspension, so that the added sulfonated lignin can fully contact with the lignin nanoparticles, and then the sulfonic acid groups are esterified with the hydroxyl and / or carboxyl groups to a certain extent to realize the chemical bond compounding of the lignin nanoparticles and the sulfonated lignin impregnated modified carbon black; the lignin nanoparticles not involved in the esterification are protonated in the acidic system to form -OH2 + and -COOH2 + The system is re-ionized due to the increase of the pH, and then the lignin nanoparticles are stably adsorbed on the surface of the carbon black to realize physical adsorption compounding. On this basis, the present application uses the shearing emulsification method to reduce the excessive compounding of the compounding material and the agglomeration phenomenon; finally, low-temperature drying is used to retain the active groups, and short-time heat treatment in an inert gas is used to promote the cross-linking and solidification between the lignin nanoparticles, the sulfonated lignin and the carbon black. The treatment temperature and time need to be appropriate, if the temperature is too high and the time is too long, the structure of the lignin nanoparticles and the sulfonated lignin is easily damaged, resulting in the failure of the modification of the carbon black surface; if the temperature is too low and the time is too short, it is difficult to achieve good solidification compounding effect, and the present application is preferably treated at 250-350℃ for 5-10min.

[0011] Optionally, in the preparation process of the modified carbon black compounding material, the mass ratio of the lignin to the carbon black is 1:1.5-2.

[0012] By using the above technical solution: the ratio can ensure that the lignin nanoparticles can fully coat the surface of the carbon black and reduce agglomeration, and during the subsequent heat treatment at 250-350℃, the ratio of 1:1.5-2 can balance the conductivity of the carbon black and the cross-linking effect of the lignin carbonization product, so that the modified carbon black compounding material with more excellent modification effect on PA6 resin is obtained.

[0013] Optionally, in the step of sulfonated lignin impregnated modified carbon black, the mass ratio of the carbon black to the sulfonated lignin is 1:1.2-1.75.

[0014] By using the above technical solution, the sulfonated lignin can fully coat the carbon black to complete the construction of the basic conductive network and promote the good dispersibility of the carbon black. When the mass ratio is >1, a small amount of free sulfonic acid groups exist in the system to lay a foundation for the subsequent combination with the lignin nanoparticles, but if the mass ratio is >1.75, the sulfonated lignin is easy to agglomerate in large quantities during the subsequent suspension mixing process, which affects the yield of the modified carbon black compounding material.

[0015] Optionally, in the step of preparing the silane coupling agent hydrolysate, the amount of silane coupling agent added is 0.1-0.3 times the mass of carbon black.

[0016] Compared to the conventional addition of 3-5% silane coupling agent for carbon black modification, the present invention uses an appropriate excess (0.1-0.3 times the mass of carbon black) of silane coupling agent, which can better improve the antistatic properties, mechanical properties and water absorption resistance of antistatic nylon materials, and is therefore preferred.

[0017] Optionally, the silane coupling agent is selected from one or a mixture of two of silane coupling agents KH-550 and KH-560.

[0018] Using the above technical solution, KH-550 and KH-560 are both common silane coupling agents. The former utilizes the reaction between -NH2 and -COOH at the PA6 end, while the latter contains epoxy groups that can combine with lignin phenolic hydroxyl groups. Both are readily soluble in water and can be compounded with carbon black in water, thereby improving the compatibility between carbon black and PA6 resin and reducing the water absorption resistance of antistatic nylon materials. When the two are used simultaneously in a 3:1 ratio, the resulting antistatic nylon material exhibits superior performance, and therefore they are considered a further preferred option.

[0019] Optionally, in the step of preparing lignin nanoparticles, the mass concentration of sodium hydroxide is 20-30 wt%.

[0020] In this invention, if the concentration of sodium hydroxide is too low, it can easily lead to uneven degradation of lignin. If the concentration of sodium hydroxide is too high, lignin can easily trigger side reactions. Within the above-mentioned mass concentration range of 20-30 wt%, the β-O-4 bonds in lignin can be fully broken, and the lignin can be depolymerized into fragments of appropriate molecular weight to form a uniform nanoparticle precursor.

[0021] Optionally, in the step of preparing lignin nanoparticles, the volume ratio of alcohol to water in the aqueous alcohol solution is 1:2-3.

[0022] Using the above technical solution, water in the alcohol-water solution is mainly used to ionize the phenolic hydroxyl groups of lignin and promote their depolymerization, while ethanol is mainly used to reduce the polarity of the solution, inhibit excessive hydrogen bonding, and make the nucleation sites evenly distributed during acid precipitation, avoiding local oversaturation that leads to agglomeration. Therefore, water plays a dominant role in this invention, while alcohol is used as an auxiliary agent, with a volume ratio of 1:2-3 being preferable.

[0023] Optionally, in the step of preparing lignin nanoparticles, the processing aid is selected from one or more of sodium thiosulfate, sodium sulfite, sodium sulfide, sodium hydrosulfide, urea, formic acid, sodium carbonate, and polyethylene glycol.

[0024] Sodium hydroxide exhibits strong alkalinity in aqueous alcohol solutions, which may lead to side reactions and the formation of byproducts such as halogenated hydrocarbons during subsequent neutralization, affecting the purity of lignin nanoparticles. Sodium thiosulfate, with its reducing and nucleophilic properties, can effectively control the reaction pathway in this invention to reduce side reactions and improve the yield of lignin nanoparticles. Sodium sulfite, sodium sulfide, and sodium hydrosulfide also possess reducing properties and can block the formation of halogenated hydrocarbons. Urea and formic acid can disperse lignin molecules through hydrogen bonding, reducing local reaction concentrations and thus minimizing the formation of halogenated hydrocarbons. The probability of hydrocarbon formation; sodium carbonate mainly acts as a weak acid buffer to adjust the pH value of the reaction system. In the conversion reaction with calcium lignin sulfonate, it can effectively replace chloride in the reaction; polyethylene glycol can reduce the contact between halogen and lignin by coating the reactive sites, and at the same time promote the uniform dispersion of lignin in alkaline solution. The above processing aids can all reduce the occurrence of by-products. Among them, polyethylene glycol can continue to act when suspension one and suspension two are mixed, slowing down the rate of carbon black agglomeration. Therefore, this invention regards it as a further preferred option.

[0025] Optionally, in the step of impregnating modified carbon black with sulfonated lignin, polyethylene glycol is added simultaneously when the carbon black is added to the sulfonated lignin.

[0026] This invention utilizes the long-chain structure of polyethylene glycol to entangle sulfonated lignin, thereby increasing the particle spacing. In addition, the terminal hydroxyl groups of polyethylene glycol can form a hydrogen bond network with carbon black, improving the dispersibility of carbon black during the impregnation process and thus enhancing the impregnation effect of carbon black.

[0027] Optionally, in the step of impregnating modified carbon black with sulfonated lignin, the ultrasonic dispersion power is 300-400w and the ultrasonic time is 15-20min.

[0028] Using the above technical solution, if the ultrasonic power is too low and the time is too short, it is difficult to effectively break up the soft agglomerates of carbon black. If the ultrasonic power is too high and the time is too long, it will cause the sulfonated lignin structure to break. In order to obtain modified carbon black with better impregnation effect, the present invention further limits the parameters of ultrasonic dispersion.

[0029] Secondly, the present invention provides a method for preparing an antistatic nylon material, which is used to prepare an antistatic nylon material including the above-mentioned method, comprising the following steps: mixing PA6, modified carbon black composite material and coupling agent and feeding them into an extruder, controlling the temperature of the feeding section to be 200-220℃, the temperature of the compression section to be 230-250℃, the temperature of the homogenization section to be 240-260℃, and the temperature of the extruder head to be 80-100℃, and obtaining the antistatic nylon material after extrusion granulation.

[0030] Using the above technical solution, the present invention ensures that the material enters in a solid state at a temperature slightly below the melting point of PA6 in the feeding section, avoiding premature melting and blockage of the feeding section; the temperature is raised to 230-250℃ in the compression section to ensure complete melting of PA6 and promote thorough mixing of the modified carbon black composite material; the homogenization section is set at 240-260℃ to further promote the sulfonic acid group to catalyze the crosslinking of PA6, improve the melt strength, and the lignin nanoparticles can absorb shear heat to a certain extent to avoid local overheating; finally, the die head temperature is set at 80-100℃ to avoid extreme cold embrittlement and improve the mechanical strength of the final product.

[0031] In summary, the present invention has the following beneficial effects: 1. This invention uses a modified carbon black composite material mainly composed of lignin nanoparticles and carbon black modified by sulfonated lignin impregnation. Without the need for additional dispersing agents, it can produce antistatic nylon materials with excellent mechanical properties, antistatic properties, flame retardant properties and water absorption resistance. This effectively solves the technical problem that adding antistatic agents in the prior art will affect the mechanical properties of the resin.

[0032] 2. The modified carbon black composite material used in this invention utilizes the stability and controllability of the liquid system to prepare lignin nanoparticles, sulfonated lignin impregnated carbon black, and silane coupling agent hydrolysate. The composite material is then achieved by sequentially mixing the two suspensions, adding the silane coupling agent hydrolysate, shearing emulsification, filtration, drying, and short-time heat treatment. The operation is simple and the process is controllable. The modified carbon black composite material obtained in this way can effectively improve the various properties of PA6 resin.

[0033] 3. The antistatic nylon material of the present invention is prepared by strictly controlling the extrusion granulation process parameters to ensure that all materials are fully dispersed, thereby ensuring that the antistatic nylon material has excellent mechanical properties, antistatic properties, flame retardant properties and water absorption resistance. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] The raw materials used in this invention are mainly commercially available products, as detailed below: PA6: Uses German Lanxess Durethan B30S.

[0036] Silane coupling agents: Taking silane coupling agents KH-550 and KH-560 as examples, both were purchased from Hangzhou Jessica Chemical Co., Ltd., with a purity of ≥98%.

[0037] Carbon black: Purchased from Tianjin Huayuan Chemical Technology Co., Ltd., model is conductive carbon black, CAS number is 1333-86-4, particle size is 20-40nm, purity ≥99%.

[0038] Lignin: Purchased from Shandong Daitian Engineering Materials Co., Ltd., product name is wood fiber, item number is 09, environmental protection level is qualified.

[0039] Sulfonated lignin: Purchased from Aladdin, product name sodium lignin sulfonate, CAS number 8061-51-6, item number S140863.

[0040] Sodium hydroxide: purchased from Aladdin, CAS No. 1310-73-2, catalog No. S111498, superior grade reagent, purity ≥96%.

[0041] Alcohol-water solution: This refers to an aqueous solution of an alcohol, wherein the alcohol can be selected from one or more of methanol, ethanol, and propanol; this invention uses ethanol-water as an example for illustration. The ethanol was purchased from Aladdin, CAS number 64-17-5, catalog number E111977, with a purity ≥99.9%; the water was deionized water.

[0042] Processing aids: These can be selected from one or more of sodium thiosulfate, sodium sulfite, sodium sulfide, sodium hydrosulfide, urea, formic acid, sodium carbonate, and polyethylene glycol. This invention uses sodium thiosulfate and polyethylene glycol as examples. Sodium thiosulfate is purchased from Aladdin, CAS number 7772-98-7, catalog number S100824, anhydrous grade, purity ≥99%. Polyethylene glycol is purchased from Aladdin, CAS number 25322-68-3, specifically using PEG-400 with catalog number P103737 as an example.

[0043] Water: Deionized water prepared on the same day.

[0044] The present invention will be further described in detail below with reference to embodiments and comparative examples.

[0045] Example Example 1 This embodiment provides an antistatic nylon material comprising the following components by weight: 85 parts PA6 and 15 parts modified carbon black composite. The modified carbon black composite is mainly composed of lignin nanoparticles, carbon black modified by sulfonated lignin impregnation, and KH-550.

[0046] The preparation method of the above-mentioned antistatic nylon material includes the following steps: (I) Preparation of modified carbon black composite material: ① Preparation of lignin nanoparticles (using 100g of lignin raw material as an example): 100g of lignin was added to a 20wt% sodium hydroxide aqueous solution (1L, made of 250mL ethanol and 750mL deionized water), and 3g of processing aid (PEG-400) was added and mixed evenly. The mixture was heated to 65℃ and hydrothermally degraded the lignin for 1 hour. The lignin filtrate was collected by filtration. The system was neutralized to pH 2 by slowly adding hydrochloric acid, and a suspension containing lignin nanoparticles was collected. ② Sulfonated lignin impregnated modified carbon black (prepared using 150g of carbon black raw material as an example): Dissolve 180g of sodium lignin sulfonate in 2L of water to form a sulfonated lignin aqueous solution. Add 150g of carbon black to the sulfonated lignin aqueous solution and control the ultrasonic power to 300w for ultrasonic dispersion treatment for 15min. After ultrasonic dispersion and mixing is completed, keep stirring (600rpm) and impregnate for 8h to obtain a suspension containing sulfonated lignin-impregnated modified carbon black. ③ Preparation of KH-550 hydrolysate: Mix 15g of KH-550 with 1L of water, keep stirring (600rpm), and hydrolyze at 60℃ for 2h to obtain silane coupling agent hydrolysate; ④ Harvesting composite materials: Slowly add suspension II to suspension I. Specifically, divide suspension II into 3 equal parts. Keep suspension I stirring (600 rpm). Add the 3 parts of suspension II in sequence. After each part is added, continue stirring for 5 minutes before adding the next part. After the last part is added, add the silane coupling agent hydrolysate all at once. After mixing, shear emulsify (5000 rpm) for 1 hour. After filtration, dry the filter residue at 65℃ (moisture content ≤0.5%). Then, under nitrogen protection, heat the mixture to 250℃ at a rate of 10℃ / min and maintain it at 250℃ for 10 minutes. Allow it to cool naturally to room temperature. Harvest the material that passes through a 60-mesh sieve to obtain the modified carbon black composite material. (II) Preparation of antistatic nylon materials: First, PA6 is placed in an 80℃ oven for hot air drying for 24 hours to obtain dried PA6 material. Then, the dried PA6 material and modified carbon black composite material are mixed and fed into an extruder. The temperature of the feeding section is controlled at 200℃, the temperature of the compression section is 230℃, the temperature of the homogenization section is 240℃, and the temperature of the extruder head is 80℃. After extrusion granulation, antistatic nylon material is obtained.

[0047] Example 2 This embodiment provides an antistatic nylon material comprising the following components by weight: 87 parts PA6 and 13 parts modified carbon black composite. The modified carbon black composite is mainly composed of lignin nanoparticles, carbon black modified by sulfonated lignin impregnation, and KH-550.

[0048] The preparation method of the above-mentioned antistatic nylon material includes the following steps: (a) The preparation of the modified carbon black composite material is the same as in Example 1; (II) Preparation of antistatic nylon materials: First, PA6 is placed in an 80℃ oven for hot air drying for 24 hours to obtain dried PA6 material. Then, the dried PA6 material and modified carbon black composite material are mixed and fed into an extruder. The temperature of the feeding section is controlled at 210℃, the temperature of the compression section is 240℃, the temperature of the homogenization section is 250℃, and the temperature of the extruder head is 90℃. After extrusion granulation, antistatic nylon material is obtained.

[0049] Example 3 This embodiment provides an antistatic nylon material comprising the following components by weight: 87 parts PA6 and 13 parts modified carbon black composite. The modified carbon black composite is mainly composed of lignin nanoparticles, carbon black modified by sulfonated lignin impregnation, and KH-560.

[0050] The preparation method of the above-mentioned antistatic nylon material includes the following steps: (a) The preparation of modified carbon black composite material is the same as in Example 1, except that KH-550 is replaced with an equal amount of KH-560; (II) Preparation of antistatic nylon materials: First, PA6 is placed in an 80℃ oven for hot air drying for 24 hours to obtain dried PA6 material. Then, the dried PA6 material and modified carbon black composite material are mixed and fed into an extruder. The temperature of the feeding section is controlled at 210℃, the temperature of the compression section is 240℃, the temperature of the homogenization section is 250℃, and the temperature of the extruder head is 90℃. After extrusion granulation, antistatic nylon material is obtained.

[0051] Example 4 This embodiment provides an antistatic nylon material comprising the following components by weight: 87 parts PA6 and 13 parts modified carbon black composite. The modified carbon black composite is mainly composed of lignin nanoparticles, carbon black modified by sulfonated lignin impregnation, and a silane coupling agent. The silane coupling agent is a mixture of KH-550 and KH-560 in a mass ratio of 3:1.

[0052] The preparation method of the above-mentioned antistatic nylon material includes the following steps: (a) The preparation of modified carbon black composite material is the same as in Example 1, except that KH-550 is replaced with an equal amount of a mixture prepared by mixing KH-550 and KH-560 in a mass ratio of 3:1; (II) Preparation of antistatic nylon materials: First, PA6 is placed in an 80℃ oven for hot air drying for 24 hours to obtain dried PA6 material. Then, the dried PA6 material and modified carbon black composite material are mixed and fed into an extruder. The temperature of the feeding section is controlled at 210℃, the temperature of the compression section is 240℃, the temperature of the homogenization section is 250℃, and the temperature of the extruder head is 90℃. After extrusion granulation, antistatic nylon material is obtained.

[0053] Example 5 This embodiment provides an antistatic nylon material comprising the following components by weight: 90 parts PA6 and 10 parts modified carbon black composite. The modified carbon black composite is mainly composed of lignin nanoparticles, carbon black modified by sulfonated lignin impregnation, and KH-560.

[0054] The preparation method of the above-mentioned antistatic nylon material includes the following steps: (a) The preparation of the modified carbon black composite material is the same as in Example 1; (II) Preparation of antistatic nylon materials: First, PA6 is placed in an 80℃ oven for hot air drying for 24 hours to obtain dried PA6 material. Then, the dried PA6 material and modified carbon black composite material are mixed and fed into an extruder. The temperature of the feeding section is controlled at 220℃, the temperature of the compression section is 250℃, the temperature of the homogenization section is 260℃, and the temperature of the extruder head is 100℃. After extrusion granulation, antistatic nylon material is obtained.

[0055] Examples 6-17 Examples 6-17 are based on Example 4, with adjustments made to the preparation process parameters of the modified carbon black composite material. For specific adjustments, please refer to Table 1 below.

[0056]

[0057] Example 18 Based on Example 6, in this embodiment, the processing aid for preparing lignin nanoparticles from the modified carbon black composite material is replaced with an equal amount of sodium thiosulfate.

[0058] Example 19 Based on Example 6, in this embodiment, during the step of impregnating modified carbon black with sulfonated lignin, 3g of PEG-400 is added simultaneously when the carbon black is added to the sulfonated lignin.

[0059] Example 20 This embodiment adjusts the "harvesting composite material" step of the modified carbon black composite material based on Example 6. The specific steps are as follows: Slowly add suspension one to suspension two. Specifically, divide suspension one into three equal parts. Keep suspension two stirred (600 rpm). Add the three parts of suspension one in sequence, stirring for 5 minutes after each part is added before adding the next part. After the last part is added and mixed well, shear emulsification (5000 rpm) is performed for 1 hour. After filtration, place the filter residue at 65℃ to dry (moisture content ≤0.5%). Then, under nitrogen protection, heat the mixture to 250℃ at a rate of 10℃ / min and maintain it at 250℃ for 10 minutes. Allow it to cool naturally to room temperature. The material that passes through a 60-mesh sieve is obtained as the modified carbon black composite material.

[0060] Example 21 This embodiment adjusts the "harvesting composite material" step of the modified carbon black composite material based on Example 6. The specific steps are as follows: Suspension II was quickly added to Suspension I. Then, stirring was started (600 rpm) for 10 minutes, followed by shear emulsification (5000 rpm) for 1 hour. After filtration, the filter residue was dried at 65°C (moisture content ≤0.5%). Then, under nitrogen protection, the temperature was increased to 250°C at a rate of 10°C / min and maintained at 250°C for 10 minutes. The mixture was then allowed to cool naturally to room temperature. The material that passed through a 60-mesh sieve was harvested, which yielded the modified carbon black composite material.

[0061] Comparative Example Comparative Example 1 Based on Example 6, this comparative example modifies the modified carbon black composite material into modified carbon black mix one. The preparation method of this modified carbon black mix one includes the following steps: 100g of lignin, 234g of sodium lignin sulfonate, 180g of carbon black, and 36g of silane coupling agent (27g of KH-550 and 9g of KH-560) were added to 4L of water and mixed evenly. The mixture was ultrasonically dispersed for 18 minutes at a power of 350W. After ultrasonic dispersion and mixing, the mixture was stirred (600rpm) and impregnated for 10 hours. Then, it was sheared and emulsified (5000rpm) for 1.5 hours. After filtration, the filter residue was dried at 65℃ (moisture content ≤0.5%). Then, under nitrogen protection, the temperature was increased to 300℃ at a rate of 10℃ / min and maintained at 300℃ for 8 minutes. The mixture was then allowed to cool naturally to room temperature. The material that passed through a 60-mesh sieve was harvested to obtain modified carbon black mixture one.

[0062] Comparative Example 2 Based on Example 6, this comparative example modifies the modified carbon black composite material to modified carbon black mix two. The preparation method of this modified carbon black mix two includes the following steps: ① Preparation of lignin nanoparticles (using 100g of lignin raw material as an example): 100g of lignin was added to a 25wt% sodium hydroxide aqueous solution (1L, composed of 250mL ethanol and 750mL deionized water), and 3g of processing aid (PEG-400) was added and mixed evenly. The mixture was heated to 65℃ and hydrothermally degraded the lignin for 1 hour. The lignin filtrate was collected by filtration, and the system was neutralized to pH 2.5 by slowly adding hydrochloric acid. The filter residue was collected by filtration and dried at 65℃ (moisture content ≤0.5%) to obtain lignin nanoparticles. ② Sulfonated lignin impregnated modified carbon black (prepared using 180g of carbon black raw material as an example): 234g of sodium lignin sulfonate was dissolved in 2L of water to form a sulfonated lignin aqueous solution. 150g of carbon black was added to the sulfonated lignin aqueous solution and ultrasonically dispersed for 15min with an ultrasonic power of 300w. After ultrasonic dispersion and mixing were completed, stirring (600rpm) was maintained and impregnated for 10h. The filter residue was collected by filtration and dried at 65℃ (moisture content ≤0.5%) to obtain sulfonated lignin impregnated modified carbon black. ③ Harvesting the mixed feed: The lignin nanoparticles obtained in step ①, the sulfonated lignin impregnated modified carbon black obtained in step ②, 27g KH-550 and 9g KH-560 are mixed evenly, and the mixture is heated to 300℃ at a rate of 10℃ / min under nitrogen protection, and maintained at 300℃ for 8min. After grinding, it is passed through a 60-mesh sieve to obtain the modified carbon black mixture II.

[0063] Comparative Example 3 Based on Example 6, this comparative example uses a commercially available antistatic agent instead of the modified carbon black composite material. Specifically, it uses Clariant's SAS93 from Switzerland, with an active ingredient content of 99%.

[0064] Performance testing The antistatic nylon materials obtained in Examples 1-21 and Comparative Examples 1-3 were used as samples for the following performance tests. The test results are shown in Table 2 below.

[0065] 1. Antistatic properties: The surface resistance of the sample was tested according to ANSI / ESD-S11.11-2021, using the four-probe method. The temperature and humidity of the test environment were 23±2℃ and 50±5%RH. 2. Mechanical properties: The tensile strength and elongation at break of the specimens were tested in accordance with GB / T 1040-2018, and the notched impact strength of the specimens was tested in accordance with GB / T1843-2008. 3. Flame retardant performance: Refer to the vertical flammability rating of the test specimens tested by UL94; 4. Water absorption resistance: The water absorption of the sample was tested according to GB / T 1034. The temperature and humidity of the test environment were 23±1℃ and 50±5%RH. The sample was soaked for 24h. The water absorption rate was calculated as [(M2-M1) / M1]×100%, where M1 is the mass after drying and M2 is the mass after soaking.

[0066]

[0067] By comparing the test results of Examples 1-21 and Comparative Examples 1-3 with those in Table 2, it can be seen that compared with Comparative Example 1 (where the raw materials are directly added to water for dispersion and mixing) and Comparative Example 2 (where lignin nanoparticles and sulfonated lignin-impregnated modified carbon black are directly mixed in solid form), the present invention, in the form of a composite material, has a more prominent modification effect. Compared with commercially available antistatic agents (Comparative Example 3), the present invention not only has lower surface resistance, higher tensile strength, elongation at break, and notched impact strength, but also has flame retardant effect and can effectively reduce water absorption. Therefore, the modified carbon black composite material of the present invention, composed of lignin nanoparticles, sulfonated lignin-impregnated modified carbon black, and silane coupling agent, can effectively reduce the impact of adding antistatic agents on the mechanical properties of PA6 resin, and does not require the addition of interfacial dispersants such as coupling agents, so that the obtained antistatic nylon material has excellent antistatic properties, mechanical properties, flame retardant properties, and water absorption resistance.

[0068] Comparing the test results of Examples 2 to 4, it can be seen that when the coupling agent of the present invention is a compound of silane coupling agents KH-550 and KH-560 in a mass ratio of 3:1, the surface resistivity of the obtained antistatic nylon material is reduced, while the tensile strength, elongation at break and notched impact strength are improved to a certain extent, the flame retardant rating is also increased, and the water absorption rate is reduced to a certain extent. Therefore, the present invention regards the above compounding scheme as a further preferred coupling agent.

[0069] Comparing the test results of Examples 4 with those of Examples 6 to 17, it can be seen that, in preparing the modified carbon black composite material, the present invention further specifies the mass ratio of lignin to carbon black as 1:1.5-2, the mass ratio of carbon black to sulfonated lignin as 1:1.2-1.75, the amount of silane coupling agent added as 0.1-0.3 times the mass of carbon black, the mass concentration of sodium hydroxide as 20-30 wt%, the volume ratio of alcohol to water in the alcohol-water solution as 1:2-3, and controls the heat treatment temperature at 250-350℃, thereby obtaining an antistatic nylon material with superior antistatic properties, mechanical properties, flame retardant properties, and water absorption resistance. Therefore, this is considered a further preferred option.

[0070] Comparing the test results of Example 6 with those of Examples 18 to 19, it can be seen that in the step of preparing lignin nanoparticles, the modified carbon black composite of the present invention uses polyethylene glycol, which not only reduces the generation of side reactions, but also acts on the mixing process of suspension one and suspension two. In addition, polyethylene glycol is added simultaneously in the step of impregnating modified carbon black with sulfonated lignin, and the modified carbon black composite obtained thereby has a better modification effect.

[0071] Comparing the test results of Example 6 with those of Examples 20 and 21, it can be seen that the different order of adding suspension one and suspension two during the preparation of modified carbon black composite material can affect the modification effect of the modified carbon black composite material on PA6 resin to a certain extent. Specifically, slowly adding suspension two containing sulfonated lignin-impregnated modified carbon black to suspension one containing lignin nanoparticles can promote better bonding between lignin nanoparticles and sulfonated lignin-impregnated modified carbon black. The resulting antistatic nylon material has superior antistatic properties, mechanical properties, and water absorption resistance.

[0072] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. An antistatic nylon material, characterized in that, The product comprises the following components in parts by weight: 85-90 parts of PA6 and 10-15 parts of modified carbon black composite material; the modified carbon black composite material is composed of lignin nanoparticles, carbon black modified by sulfonated lignin impregnation, and silane coupling agent.

2. The antistatic nylon material according to claim 1, characterized in that, The preparation method of the modified carbon black composite material includes the following steps: Preparation of lignin nanoparticles: lignin was added to an alcoholic aqueous solution of sodium hydroxide, and processing aids were added and mixed evenly. After heating and degradation treatment, the lignin filtrate was collected by filtration. Hydrochloric acid was slowly added to neutralize the system to pH 2-3, and a suspension containing lignin nanoparticles was collected. Sulfonated lignin impregnated modified carbon black: Sulfonated lignin is dissolved in water to form an aqueous solution of sulfonated lignin. Carbon black is added to the aqueous solution of sulfonated lignin, and after ultrasonic dispersion and mixing, it is impregnated for 8-12 hours. A suspension containing sulfonated lignin impregnated modified carbon black is then harvested. Preparation of silane coupling agent hydrolysate: Mix silane coupling agent with water and hydrolyze at 60-80℃ for 1-2 hours to obtain silane coupling agent hydrolysate; Harvesting the composite material: Slowly add suspension II to suspension I, mix well, then add silane coupling agent hydrolysate, and perform shear emulsification treatment for 1-2 hours. After filtration, dry the filter residue at low temperature, and then heat it to 250-350℃ for 5-10 minutes under the protection of inert gas to obtain the modified carbon black composite material.

3. The antistatic nylon material according to claim 2, characterized in that, In the preparation process of the modified carbon black composite material, the mass ratio of lignin to carbon black is 1:1.5-2.

4. The antistatic nylon material according to claim 2, characterized in that, In the step of impregnating modified carbon black with sulfonated lignin, the mass ratio of carbon black to sulfonated lignin is 1:1.2-1.

75.

5. The antistatic nylon material according to claim 2, characterized in that, In the step of preparing the silane coupling agent hydrolysate, the amount of silane coupling agent added is 0.1-0.3 times the mass of carbon black.

6. The antistatic nylon material according to claim 2, characterized in that, In the step of preparing lignin nanoparticles, the mass concentration of sodium hydroxide is 20-30 wt%.

7. The antistatic nylon material according to claim 6, characterized in that, In the step of preparing lignin nanoparticles, the volume ratio of alcohol to water in the alcohol-water solution is 1:2-3.

8. The antistatic nylon material according to claim 2, characterized in that, In the step of impregnating modified carbon black with sulfonated lignin, polyethylene glycol is added simultaneously when the carbon black is added to the sulfonated lignin.

9. The antistatic nylon material according to claim 2, characterized in that, In the step of impregnating modified carbon black with sulfonated lignin, the ultrasonic dispersion power is 300-400w and the ultrasonic time is 15-20min.

10. A method for preparing an antistatic nylon material, characterized in that, The preparation of an antistatic nylon material as described in any one of claims 1-9 comprises the following steps: mixing PA6, modified carbon black composite material and coupling agent and feeding them into an extruder, controlling the temperature of the feeding section to be 200-220℃, the temperature of the compression section to be 230-250℃, the temperature of the homogenization section to be 240-260℃, and the temperature of the extruder head to be 80-100℃, and obtaining the antistatic nylon material after extrusion granulation.

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