An antistatic nylon material and its preparation method

Abstract

This invention relates to the field of nylon materials technology, specifically to an antistatic nylon material and its preparation method. The antistatic nylon material comprises the following components in parts by weight: 85-90 parts PA6 and 10-15 parts modified carbon black composite material; the modified carbon black composite material is composed of lignin nanoparticles, carbon black modified by sulfonated lignin impregnation, and a silane coupling agent. This invention, by adding a specific modified carbon black composite material to PA6 resin, eliminates the need for additional dispersing agents, enabling the production of an antistatic nylon material with excellent mechanical properties, antistatic properties, flame retardant properties, and water absorption resistance. This effectively solves the technical problem in existing technologies where adding antistatic agents affects the mechanical properties of the resin.

Description

Technical Field

[0001] This invention relates to the field of nylon materials technology, and more specifically, to an antistatic nylon material and its preparation method. Background Technology

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

[0003] Nylon 6 is one of the main types of polyamides. Nylon 6 molecules are bonded by covalent bonds, and its main chain structure contains relatively few polar groups. Therefore, Nylon 6 has a high surface resistivity, reaching 10⁻⁶. 13 -10 14 Ω has poor electrical conductivity. When it comes into contact with or rubs against other substances or surfaces, it easily accumulates a large amount of static charge. This can cause minor issues such as dust accumulation, electronic device breakdown, damage to integrated circuits, and electrical discharges, or even serious accidents such as fires and explosions, significantly impacting industrial production and daily life.

[0004] To reduce the hazards of static electricity, antistatic agents are usually applied directly to the material surface or blended into polyamide resin. The former method of coating has poor durability, while the latter method of blending is prone to poor dispersion, which can lead to a decline in the mechanical properties of the material. Summary of the Invention

[0005] To address at least one of the aforementioned problems, this invention provides an antistatic nylon material and its preparation method. By adding a specific modified carbon black composite material to PA6 resin, without the need for additional dispersing agents, the antistatic and flame-retardant properties of the material are further improved while ensuring good mechanical properties, and the water absorption of the material is reduced.

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

[0007] This invention utilizes carbon black to provide a conductive pathway, lignin nanoparticles to enhance flame retardancy and mechanical properties, and sulfonated lignin to a certain extent to coat the carbon black. The silane coupling agent not only improves the dispersion of carbon black in PA6 resin, but also appropriately reduces the water absorption effect of the polar groups brought by lignin nanoparticles and sulfonated lignin. The composite design of lignin nanoparticles, sulfonated lignin-modified carbon black, and silane coupling agent avoids the defects of single fillers and further improves the dispersibility and interfacial bonding effect of modified carbon black composite material with PA6 resin. The resulting antistatic nylon material has excellent mechanical properties, antistatic properties, flame retardancy, and water absorption resistance.

[0008] Optionally, the preparation method of the modified carbon black composite material includes the following steps:

[0009] 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.

[0010] 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.

[0011] 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;

[0012] 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.

[0013] This invention employs an "alkali degradation + acid precipitation" method to achieve lignin nanoparticle formation. The operation is simple and the process is controllable. The addition of processing aids suppresses side reactions, thereby ensuring the stability of the nanoparticles. Sulfonated lignin is readily soluble in water; its aqueous solution, combined with an "ultrasound + impregnation" treatment, better promotes the coating of carbon black by sulfonated lignin, improving the hydrophilicity and dispersibility of the carbon black. The alkoxy group (-OR) of the silane coupling agent reacts with water to generate unstable silanol groups (-SiOH) and the corresponding alcohol (ROH). The silanol groups (-SiOH) readily form covalent bonds with the hydroxyl groups on the carbon black surface, thus achieving composite formation. The entire composite process of this invention is carried out in water, which facilitates full contact and participation of the reactants, resulting in better composite effects.

[0014] During the compounding process, the sulfonic acid groups in sulfonated lignin undergo a certain degree of protonation in an acidic system, forming -SO3H2. + Because aggregation is prone to occur, this invention involves slowly adding a second suspension (containing sulfonated lignin-impregnated modified carbon black) to a first suspension (containing lignin nanoparticles). This allows the pH of the first suspension to gradually increase, enabling the added sulfonated lignin to fully contact the lignin nanoparticles. Furthermore, by utilizing the characteristic that sulfonic acid groups can undergo a certain degree of esterification with hydroxyl and / or carboxyl groups, chemical bonding between the lignin nanoparticles and the sulfonated lignin-impregnated modified carbon black is achieved. The lignin nanoparticles that do not participate in the esterification reaction undergo protonation of the -OH2 functional group in an acidic system. + and -COOH2 + The system re-ionizes due to the increase in pH, which in turn promotes the stable adsorption of lignin nanoparticles on the carbon black surface to achieve physical adsorption and composite.

[0015] Based on this, the present invention utilizes shear emulsification to reduce the phenomenon of excessive agglomeration caused by over-composite materials; finally, low-temperature drying is used to retain active groups, and short-time heat treatment under inert gas promotes cross-linking and curing between lignin nanoparticles, sulfonated lignin, and carbon black. The treatment temperature and time need to be appropriate. If the temperature is too high or the time is too long, the structure of the lignin nanoparticles and sulfonated lignin is easily destroyed, leading to the failure of carbon black surface modification; if the temperature is too low or the time is too short, it is difficult to achieve a good curing and composite effect. The present invention recommends treatment at 250-350℃ for 5-10 minutes.

[0016] Optionally, in the preparation process of the modified carbon black composite material, the mass ratio of lignin to carbon black is 1:1.5-2.

[0017] Using the above technical solution: This ratio can ensure that lignin nanoparticles can fully coat the carbon black surface, reducing agglomeration. During subsequent heat treatment at 250-350℃, the ratio of 1:1.5-2 can balance the conductivity of carbon black and the cross-linking effect of lignin carbonization products, thereby obtaining a modified carbon black composite material with better modification effect on PA6 resin.

[0018] Optionally, 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.

[0019] Using the above technical solution, sulfonated lignin can fully coat carbon black, thereby completing the construction of the basic conductive network and promoting good dispersibility of carbon black. When the mass ratio is >1, a small amount of free sulfonic acid groups still exist in the system, which lays a good foundation for subsequent bonding with lignin nanoparticles. However, if the mass ratio is >1.75, sulfonated lignin is prone to agglomeration in large quantities during subsequent suspension mixing, affecting the yield of modified carbon black composite material.

[0020] 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.

[0021] 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.

[0022] Optionally, the silane coupling agent is selected from one or a mixture of two of silane coupling agents KH-550 and KH-560.

[0023] 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.

[0024] Optionally, in the step of preparing lignin nanoparticles, the mass concentration of sodium hydroxide is 20-30 wt%.

[0025] 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.

[0026] Optionally, in the step of preparing lignin nanoparticles, the volume ratio of alcohol to water in the aqueous alcohol solution is 1:2-3.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] In summary, the present invention has the following beneficial effects:

[0037] 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.

[0038] 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.

[0039] 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

[0040] 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.

[0041] The raw materials used in this invention are mainly commercially available products, as detailed below:

[0042] PA6: Uses German Lanxess Durethan B30S.

[0043] 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%.

[0044] 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%.

[0045] Lignin: Purchased from Shandong Daitian Engineering Materials Co., Ltd., product name is wood fiber, item number is 09, environmental protection level is qualified.

[0046] Sulfonated lignin: Purchased from Aladdin, product name sodium lignin sulfonate, CAS number 8061-51-6, item number S140863.

[0047] Sodium hydroxide: purchased from Aladdin, CAS No. 1310-73-2, catalog No. S111498, superior grade reagent, purity ≥96%.

[0048] 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.

[0049] 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.

[0050] Water: Deionized water prepared on the same day.

[0051] The present invention will be further described in detail below with reference to embodiments and comparative examples.

[0052] Example

[0053] Example 1

[0054] 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.

[0055] The preparation method of the above-mentioned antistatic nylon material includes the following steps:

[0056] (I) Preparation of modified carbon black composite material:

[0057] ① Preparation of lignin nanoparticles (using 100g of lignin raw material as an example):

[0058] 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.

[0059] ② Sulfonated lignin impregnated modified carbon black (prepared using 150g of carbon black raw material as an example):

[0060] 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.

[0061] 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;

[0062] ④ Harvesting the composite material:

[0063] 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.

[0064] (II) Preparation of antistatic nylon materials:

[0065] 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.

[0066] Example 2

[0067] 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.

[0068] The preparation method of the above-mentioned antistatic nylon material includes the following steps:

[0069] (a) The preparation of the modified carbon black composite material is the same as in Example 1;

[0070] (II) Preparation of antistatic nylon materials:

[0071] 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.

[0072] Example 3

[0073] 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.

[0074] The preparation method of the above-mentioned antistatic nylon material includes the following steps:

[0075] (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;

[0076] (II) Preparation of antistatic nylon materials:

[0077] 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.

[0078] Example 4

[0079] 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.

[0080] The preparation method of the above-mentioned antistatic nylon material includes the following steps:

[0081] (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;

[0082] (II) Preparation of antistatic nylon materials:

[0083] 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.

[0084] Example 5

[0085] 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.

[0086] The preparation method of the above-mentioned antistatic nylon material includes the following steps:

[0087] (a) The preparation of the modified carbon black composite material is the same as in Example 1;

[0088] (II) Preparation of antistatic nylon materials:

[0089] 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.

[0090] Examples 6-17

[0091] 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.

[0092]

[0093] Example 18

[0094] 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.

[0095] Example 19

[0096] 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.

[0097] Example 20

[0098] 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:

[0099] 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.

[0100] Example 21

[0101] 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:

[0102] 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.

[0103] Comparative Example

[0104] Comparative Example 1

[0105] 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:

[0106] 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.

[0107] Comparative Example 2

[0108] Based on Example 6, this comparative example modifies the modified carbon black composite material into modified carbon black mix two. The preparation method of this modified carbon black mix two includes the following steps:

[0109] ① Preparation of lignin nanoparticles (using 100g of lignin raw material as an example):

[0110] 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.

[0111] ② Sulfonated lignin impregnated modified carbon black (prepared using 180g of carbon black raw material as an example):

[0112] 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.

[0113] ③ Harvesting the mixed feed:

[0114] 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.

[0115] Comparative Example 3

[0116] 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%.

[0117] Performance testing

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 3. Flame retardant performance: Refer to the vertical flammability rating of the test specimens tested by UL94;

[0122] 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.

[0123]

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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 by, Components including the following weight parts: PA6 85-90 parts, modified carbon black compound 10-15 parts; The modified carbon black compound is compounded by lignin nanoparticles, carbon black modified by impregnation of sulfonated lignin and silane coupling agent; The preparation method of the modified carbon black compound comprises the following steps: Preparation of lignin nanoparticles: lignin is put into an alcohol aqueous solution of sodium hydroxide, processing aids are added and mixed uniformly, lignin filtrate is harvested after heating degradation treatment and filtration, the system is neutralized to pH 2-3 by slowly adding hydrochloric acid, and a suspension containing lignin nanoparticles is harvested; 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, mixed after ultrasonic dispersion, impregnated for 8-12 h, and a suspension containing sulfonated lignin impregnated modified carbon black is harvested; Preparation of silane coupling agent hydrolysate: silane coupling agent is mixed with water, hydrolyzed at 60-80℃ for 1-2 h, and the silane coupling agent hydrolysate is harvested; Harvesting of the compound: suspension two is slowly added to suspension one, mixed, then the silane coupling agent hydrolysate is added, treated by shear emulsification for 1-2 h, filtered, the filter residue is dried at low temperature, then heated to 250-350℃ for 5-10 min under the protection of inert gas, and the modified carbon black compound is obtained; In the preparation process of the modified carbon black compound, the mass ratio of lignin to carbon black is 1:1.5-2; in the step of sulfonated lignin impregnated modified carbon black, the mass ratio of carbon black to sulfonated lignin is 1:1.2-1.75; in the step of preparing the silane coupling agent hydrolysate, the addition amount of the silane coupling agent is 0.1-0.3 times the mass of the carbon black.

2. The antistatic nylon material according to claim 1, characterized in that, In the step of preparing lignin nanoparticles, the mass concentration of sodium hydroxide is 20-30 wt%.

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

4. The antistatic nylon material according to claim 1, wherein In the step of sulfonated lignin impregnated modified carbon black, polyethylene glycol is also added synchronously when the carbon black is put into the sulfonated lignin.

5. The antistatic nylon material according to claim 1, wherein In the step of sulfonated lignin impregnated modified carbon black, the ultrasonic dispersion power is 300-400 w, and the ultrasonic time is 15-20 min.

6. A method of producing an antistatic nylon material, characterized by, The anti-static nylon material comprising the modified carbon black compound as claimed in any one of claims 1-5, The anti-static nylon material is prepared by the following steps: PA6 dry material and modified carbon black compound are mixed and uniformly put into an extruder, the temperature of the feeding section is controlled to be 200-220℃, the temperature of the compression section is controlled to be 230-250℃, the temperature of the homogenization section is controlled to be 240-260℃, and the temperature of the extruder head is controlled to be 80-100℃, and the anti-static nylon material is obtained after extrusion granulation.

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