Antistatic flame-retardant material as well as preparation method and application thereof

Abstract

The invention provides an antistatic flame-retardant material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The preparation method comprises the following steps: modifying polyacene through polydopamine, reacting with silane coupling agent modified carbon black subjected to DOPO reaction to prepare an antistatic flame-retardant modifier, uniformly mixing the antistatic flame-retardant modifier with low-density polyethylene, a whitening agent, an antibacterial agent, a stabilizer and talcum powder, feeding into a foaming production line, introducing a butane foaming agent and food-grade monoglyceride to assist foaming, and discharging to prepare the antistatic flame-retardant material. The antistatic flame-retardant material prepared by the invention is low in resistivity, good in flame retardance, stable in heat resistance, relatively good in antistatic property, wear resistance and mechanical property, simple in preparation method, relatively low in preparation cost and wide in application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to an antistatic and flame-retardant material, a preparation method thereof, and an application thereof. Background Art

[0002] Common buffer and protection functional materials mainly include several categories such as foamed plastic buffer materials, air cushion buffer materials, paper buffer materials, and plant fiber buffer materials. Among them, plastic buffer materials are widely used because of their light weight, high strength, easy processing, low price, and good buffer and vibration absorption performance.

[0003] In addition to selecting different resin materials, buffer and protection materials also require the apparent density of various materials to meet certain requirements; they need to have good impact energy and vibration absorption, good resilience and small permanent deformation; they can withstand possible environmental factors such as temperature, humidity, acids, alkalis, oils, mildew, corrosive organic substances, and radiation; they should also ensure that they do not corrode the protected items; they are also required to have various advantages such as antistatic property, easy processing, low cost, easy recycling, and easy disposal, and meet the requirements of national environmental protection.

[0004] Foamed plastic buffer and protection materials mainly use polystyrene (PS), polyethylene (PE), polyurethane (PU), ethylene-vinyl acetate copolymer rubber and plastic (EVA), etc. Expanded polystyrene (EPS) is the most used plastic buffer material at present, with small water absorption, good water resistance, small density, good mechanical strength, etc. However, the styrene gas released during the combustion of EPS will pollute the atmospheric environment, and EPS is not resistant to multiple impacts, is relatively brittle, and has a low tensile strength. Expanded polyethylene (EPE) has a small density, good buffering performance, heat resistance, strong water absorption, relatively stable chemical properties, not easily corroded, good mechanical properties, easy to process, easy to form, recyclable, and environmentally friendly, but the price is more expensive than EPS. Polyurethane (PU) foamed plastic has good elasticity, softness, excellent chemical stability, resistance to a variety of solvents and oils, good wear resistance, and also has good processing performance, etc., but the price is relatively high. Ethylene-vinyl acetate copolymer rubber and plastic (EVA) has good buffer and vibration isolation performance, good resilience, strong toughness, heat insulation, moisture proof, non-toxic, easy to process and other characteristics, and can achieve long-term packaging protection.

[0005] With the development of society and industry, the requirements for buffer and protection functional materials are also getting higher and higher. Various buffer and protection materials with excellent characteristics such as high buffering, antistatic property, flame retardancy, degradability, environmental friendliness, and low cost have become an important development direction in the future.

[0006] EPE (expandable polyethylene, also known as pearl cotton) material has a non-crosslinked closed-cell structure, consisting of countless independent micro-porous bubbles, overcoming the disadvantages of ordinary foamed materials such as being fragile, deformable and difficult to recover, and is environmentally friendly and recyclable. EPE material is a functional high-foam polyethylene material manufactured by using low-density polyethylene (LDPE) as the main raw material and adding various functional additives through production processes such as mixing, melting, extrusion, foaming, shaping, cooling, winding, cutting, compounding, and forming. It has many advantages such as buffering and shockproofing, heat preservation, water-proof and moisture-proof, sound insulation, anti-friction, anti-aging, corrosion resistance, good plasticity, strong toughness, easy processing, recyclability, degradability, and no pollution. It is an environmentally friendly packaging and protective functional material and is widely used in industries such as electronic appliances, food, agricultural products, medicine, semiconductors and microelectronics, precision instruments, medical devices, biological products, glass ceramics, hardware and general merchandise, cosmetics, gift products, and photovoltaic, and is an ideal substitute for traditional products.

[0007] EPE materials generally do not have flame retardant properties and belong to flammable products. Although there are some manufacturers in the market selling flame retardant EPE materials, they generally use halogen-containing flame retardant systems and basically do not reach the flame retardant level of plastic materials, still having serious safety hazards and environmental problems. Summary of the Invention

[0008] The purpose of the present invention is to provide an antistatic and flame retardant material, its preparation method and application, which have low resistivity, good flame retardancy, heat resistance stability, and have good antistatic, wear-resistant and mechanical properties. The preparation method is simple, the preparation cost is low, and it has broad application prospects.

[0009] The technical solution of the present invention is realized as follows:

[0010] The present invention provides a preparation method of an antistatic and flame retardant material. Polyacene is modified by polydopamine and reacts with carbon black modified by a silane coupling agent reacted with DOPO to obtain an antistatic and flame retardant modifier. After being uniformly mixed with low-density polyethylene, a whitening agent, an antibacterial agent, a stabilizer, and talcum powder, it enters a foaming production line, and a butane-based foaming agent and food-grade monoglyceride are introduced to assist foaming, and then the product is discharged to obtain the antistatic and flame retardant material.

[0011] As a further improvement of the present invention, it includes the following steps:

[0012] S1. Preparation of polyacene: Phenol and formaldehyde are mixed evenly, ammonia water is added, heated under reflux and stirred for reaction, the pH value of the solution is adjusted, the reaction is continued by heating, zinc chloride is added, heated and cured, thermally cracked, pulverized, and ball milled to obtain polyacene;

[0013] S2. Preparation of polydopamine-modified polyacene: Add polyacene into water, disperse it evenly by ultrasonic wave, add dopamine hydrochloride and a catalyst, heat and stir for reaction, centrifuge, wash, and dry to obtain polydopamine-modified polyacene;

[0014] S3. Preparation of modified carbon black: Add carbon black into ethanol, disperse it evenly by ultrasonic wave, add a silane coupling agent, heat and stir for reaction, centrifuge, wash, and dry to obtain modified carbon black;

[0015] S4. Preparation of DOPO-modified carbon black: Add modified carbon black and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide into tetrahydrofuran, stir for reaction, centrifuge, wash, and dry to obtain DOPO-modified carbon black;

[0016] S5. Preparation of antistatic and flame-retardant modifier: Add polydopamine-modified polyacene and DOPO-modified carbon black into acetonitrile, stir for reaction, centrifuge, wash, and dry to obtain an antistatic and flame-retardant modifier;

[0017] S6. Preparation of antistatic and flame-retardant material: Dry low-density polyethylene, mix it evenly with an antistatic and flame-retardant modifier, a whitening agent, an antibacterial agent, a stabilizer, and talcum powder, then send it into a foaming production line, introduce a butane-based foaming agent and food-grade monoglyceride to assist foaming, and discharge to obtain an antistatic and flame-retardant material.

[0018] As a further improvement of the present invention, in step S1, the molar ratio of phenol to formaldehyde is 1:1 - 1.2, the time for the heating reflux stirring reaction is 2 - 4 h, the pH value of the adjusted solution is 4 - 6, the time for the continued heating reaction is 2 - 4 h, the addition amount of zinc chloride is 1 - 2 wt% of the total mass of the system, the temperature for heat curing is 65 - 75 °C, the time is 20 - 24 h, the temperature for pyrolysis is 1000 - 1200 °C, the time is 2 - 4 h, and the time for ball milling is 1 - 2 h.

[0019] As a further improvement of the present invention, in step S2, the mass ratio of polyacene, dopamine hydrochloride, and the catalyst is 10:2 - 4:0.5 - 1, the temperature for the heating and stirring reaction is 40 - 50 °C, and the time is 2 - 4 h; the catalyst is a Tris-HCl solution with pH = 8.5 - 9.5.

[0020] As a further improvement of the present invention, in step S3, the mass ratio of carbon black to the silane coupling agent is 10:2 - 3, the silane coupling agent is a mixture of KH570 and KH560 with a mass ratio of 3 - 5:6, the temperature for the heating and stirring reaction is 45 - 55 °C, and the time is 2 - 3 h.

[0021] As a further improvement of the present invention, in step S4, the mass ratio of the modified carbon black to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 7-10:1-2, and the stirring reaction time is 3-5 h.

[0022] As a further improvement of the present invention, in step S5, the mass ratio of the polydopamine-modified polyacene to the DOPO-modified carbon black is 10:3-5, and the stirring reaction time is 12-15 h.

[0023] As a further improvement of the present invention, in step S6, the mass ratio of the antistatic and flame-retardant modifier, low-density polyethylene, whitening agent, antibacterial agent, stabilizer, talcum powder, butane foaming agent, and monoglyceride is 4-5:100:0.5-1:1-2:0.5-1:2-4:1-1.5:0.5-1. The drying temperature is 110-130 °C, and the time is 1-2 h. The temperature of the foaming production line is divided into 11 zoning and temperature-regulating zones. The temperature of zones 1-3 is 85-110 °C, the temperature of zones 4-8 is 180-200 °C, the temperature of the temperature-regulating zone is 140-160 °C, the temperature of zones 9-11 is 170-190 °C, the die head discharge temperature is 150-130 °C, and the winding speed is 1-1.3 m / s.

[0024] The present invention further protects an antistatic and flame-retardant material prepared by the above preparation method.

[0025] The present invention further protects the application of the above antistatic and flame-retardant material in the preparation of plastics for coal mines.

[0026] The present invention has the following beneficial effects:

[0027] The hard carbon with a graphite-like structure obtained by pyrolyzing phenolic resin at 1100 °C. As the pyrolysis temperature increases, phenolic resin first undergoes intermolecular dehydration, then intramolecular dehydration and dehydrogenation reactions, and finally forms polyacene nanoparticles with a conjugated structure. This kind of structure has a very low hydrogen element content and is non-toxic itself. When heated, it will not generate toxic and corrosive gases and can greatly reduce the smoke generation amount. It has good thermal stability to heat and oxygen. When the composite material burns in the air, there is no black smoke, no dripping, and carbonization, effectively improving the combustion behavior of polyethylene.

[0028] When the composite material burns, the flame-retardant modifier particles form a thick protective carbon layer on the surface of the burning polymer, reducing the mass and heat transfer between the gas phase and the condensed phase, reducing the amount of fuel transported to the flame, and reducing the heating efficiency of the flame on the polymer, reducing the diffusion of oxygen to the condensed phase and slowing down the decomposition rate of the condensed phase, thereby reducing the flammability of the polymer. At the same time, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) loaded on the modifier releases phosphorus-containing free radicals and phenoxy free radicals in a high-temperature environment. These free radicals can quench the combustion chain reaction in the gas phase, thereby achieving a flame-retardant effect; polydopamine inhibits the progress of the combustion chain reaction by capturing free radicals, promoting the formation of more carbon layers during the combustion of the material. This carbon layer can isolate oxygen and heat and prevent the further combustion of the material. DOPO and polydopamine can fully exert the synergistic flame-retardant effect, thus significantly enhancing the flame-retardant effect of the prepared composite material.

[0029] In the present invention, carbon black is modified with a silane coupling agent with a double bond and a silane coupling agent with an epoxy group, so that DOPO can react with the modified carbon black, and polydopamine-modified polyacene can react with DOPO-modified carbon black to obtain an organic composite. Compared with directly adding DOPO and polydopamine particles for blending, the present invention greatly improves the compatibility of DOPO and polydopamine, effectively avoiding the problem of reduced mechanical properties of the prepared composite material. At the same time, after being modified by the present invention, the modifier enhances the mechanical properties of the composite material to a certain extent.

[0030] In addition, DOPO-modified carbon black can form an electrical network, significantly reducing the volume resistivity of the material, reducing the friction coefficient on the surface of the material, thereby reducing the generation of static electricity. Therefore, the antistatic performance of DOPO-modified carbon black is significantly enhanced. At the same time, polydopamine has the characteristics of a surfactant, with both polar and non-polar groups in its structure, which enables them to form an antistatic layer on the surface of the material. Therefore, the antistatic performance of polydopamine-modified polyacene is also enhanced.

[0031] The distance between adjacent modifier particles of the antistatic and flame-retardant modifier prepared by the present invention in the composite material is reduced, and even contact between nanoparticles occurs, forming a conductive path in the composite material through tunneling effect or electron transition. Since the modifier is amorphous graphite-like carbon with a large specific surface area, when compounded with polyethylene, the surface adsorption energy between particles is large. At the same time, the benzene rings and conjugated structures of polydopamine and polyacene enable the modifier particles to be evenly dispersed in polyethylene, improving the compatibility and reducing the distance between particles, making it easier for conductive carriers to migrate, so that the composite material can form a conductive network, significantly reducing the resistivity and having conductivity, thus greatly improving the antistatic performance of the composite material.

[0032] The antistatic and flame-retardant modifier prepared by the present invention can also form a good interfacial bond with the polyethylene polymer matrix due to its high specific surface area and high surface energy. This interfacial bond can effectively transfer stress and disperse stress concentration points, thereby improving the overall mechanical properties of the material. It can connect both sides of the crack through a bridging effect and further prevent the crack from expanding, thus achieving a good toughening effect.

[0033] The antistatic and flame-retardant material prepared by the present invention has a low resistivity, good flame retardancy, heat stability, and has good antistatic, wear-resistant and mechanical properties. The preparation method is simple and the preparation cost is low, having broad application prospects. Detailed implementation manners

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] The polyethylene is S1003 from Yanshan Petrochemical, purchased from Dongguan Jinshixiang Plastic Raw Materials Co., Ltd.

[0036] Example 1

[0037] This example provides a preparation method of an antistatic and flame-retardant material, including the following steps:

[0038] S1. Preparation of polyacene: Mix 1 mol of phenol and 1 mol of formaldehyde evenly, add 5 mL of ammonia water, heat under reflux and stir for 2 h, adjust the pH value of the solution to 4, continue heating and reacting for 2 h, add zinc chloride, and the addition amount is 1 wt% of the total mass of the system. Heat to 65 °C and cure for 20 h. Under nitrogen protection, pyrolyze at 1100 °C for 2 h, pulverize, and ball mill for 1 h to obtain polyacene;

[0039] S2. Preparation of polydopamine-modified polyacene: Add 10 g of polyacene to 200 mL of water, disperse it by ultrasonic wave at 1500 W for 15 min, add 2 g of dopamine hydrochloride and 0.5 g of catalyst, heat to 40 °C, stir and react for 2 h, centrifuge, wash, and dry to obtain polydopamine-modified polyacene;

[0040] The catalyst is a Tris-HCl solution with pH = 8.5;

[0041] S3. Preparation of modified carbon black: Add 10 g of carbon black to 200 mL of ethanol, disperse it by ultrasonic wave at 1000 W for 15 min, add 2 g of silane coupling agent, heat to 45 °C, stir and react for 2 h, centrifuge, wash, and dry to obtain modified carbon black;

[0042] The silane coupling agent is a mixture of KH570 and KH560, and the mass ratio is 3:6;

[0043] S4. Preparation of DOPO-modified carbon black: Add 7 g of modified carbon black and 1 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to 200 mL of tetrahydrofuran, stir and react for 3 h, centrifuge, wash, and dry to obtain DOPO-modified carbon black;

[0044] S5. Preparation of antistatic and flame-retardant modifier: Add 10 g of polydopamine-modified polyacene and 3 g of DOPO-modified carbon black to 200 mL of acetonitrile, stir and react for 12 h, centrifuge, wash, and dry to obtain the antistatic and flame-retardant modifier;

[0045] S6. Preparation of antistatic and flame-retardant material: Put 100 g of low-density polyethylene into a dryer and dry it at a temperature of 110 °C. After naturally cooling to 60 °C, mix it evenly with 4 g of antistatic and flame-retardant modifier, 0.5 g of plastic brightener OB, 1 g of 5-chloro-2-methyl-4-isothiazolin-3-one, 0.5 g of octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate, and 2 g of talc powder, and then put it into a foaming production line. The temperature of the foaming production line is divided into 11 zones and temperature control zones. The temperature of zones 1-3 is 85 °C, the temperature of zones 4-8 is 180 °C, the temperature of the temperature control zone is 140 °C, the temperature of zones 9-11 is 170 °C, the temperature of the die head for discharging is 150 °C. The metering pump is respectively fed with 1 g of n-butane and 0.5 g of food-grade monoglyceride to assist foaming for 5 h, then discharge the material, and the winding speed can reach 1 m / s to obtain the antistatic and flame-retardant material.

[0046] Example 2

[0047] This example provides a preparation method of an antistatic and flame-retardant material, including the following steps:

[0048] S1. Preparation of polyacene: Mix 1 mol of phenol and 1.2 mol of formaldehyde evenly, add 7 mL of ammonia water, heat under reflux and stir for 4 h, adjust the pH value of the solution to 6, continue to heat and react for 4 h, add zinc chloride, and the addition amount is 2 wt% of the total mass of the system. Heat to 75 °C and cure for 24 h. Under nitrogen protection, pyrolyze at 1200 °C for 4 h, pulverize, and ball mill for 2 h to obtain polyacene;

[0049] S2. Preparation of polydopamine-modified polyacene: Add 10 g of polyacene to 200 mL of water, disperse it by ultrasonic wave at 1500 W for 15 min, add 4 g of dopamine hydrochloride and 1 g of catalyst, heat to 50 °C, stir and react for 4 h, centrifuge, wash, and dry to obtain polydopamine-modified polyacene;

[0050] The catalyst is a Tris-HCl solution with pH = 9.5;

[0051] S3. Preparation of modified carbon black: Add 10 g of carbon black into 200 mL of ethanol, disperse it by ultrasonic wave at 1000 W for 15 min, add 3 g of silane coupling agent, heat it to 55 °C, stir and react for 3 h, centrifuge, wash, and dry to obtain modified carbon black;

[0052] The silane coupling agent is a mixture of KH570 and KH560, and the mass ratio is 5:6;

[0053] S4. Preparation of DOPO-modified carbon black: Add 10 g of modified carbon black and 2 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide into 200 mL of tetrahydrofuran, stir and react for 5 h, centrifuge, wash, and dry to obtain DOPO-modified carbon black;

[0054] S5. Preparation of antistatic and flame-retardant modifier: Add 10 g of polydopamine-modified polyacene and 5 g of DOPO-modified carbon black into 200 mL of acetonitrile, stir and react for 15 h, centrifuge, wash, and dry to obtain antistatic and flame-retardant modifier;

[0055] S6. Preparation of antistatic and flame-retardant material: Put 100 g of low-density polyethylene into a dryer for drying at a temperature of 130 °C. After naturally cooling to 80 °C, mix it evenly with 5 g of antistatic and flame-retardant modifier, 1 g of plastic brightener OB, 2 g of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one, 1 g of 2,6-di-tert-butyl-p-cresol, and 4 g of talcum powder, and then put it into a foaming production line. The temperature of the foaming production line is divided into 11 partition and temperature adjustment zones. The temperature of zones 1-3 is 110 °C, the temperature of zones 4-8 is 200 °C, the temperature of the temperature adjustment zone is 160 °C, the temperature of zones 9-11 is 190 °C, the temperature of the die head discharging is 130 °C. The metering pump respectively feeds 1.5 g of n-butane and 1 g of food-grade monoglyceride to assist foaming for 5 h, discharge the material, and the winding speed can reach 1.3 m / s to obtain the antistatic and flame-retardant material.

[0056] Example 3

[0057] This example provides a preparation method of an antistatic and flame-retardant material, including the following steps:

[0058] S1. Preparation of polyacene: Mix 1 mol of phenol and 1.1 mol of formaldehyde evenly, add 6 mL of ammonia water, heat under reflux and stir for 3 h, adjust the pH value of the solution to 5, continue heating and reacting for 3 h, add zinc chloride, and the addition amount is 1.5 wt% of the total mass of the system. Heat to 70 °C and cure for 22 h. Under nitrogen protection, pyrolyze at 1150 °C for 3 h, pulverize, and ball mill for 1.5 h to obtain polyacene;

[0059] S2. Preparation of Polydopamine-Modified Polyacene: Add 10 g of polyacene into 200 mL of water, disperse it by ultrasonic wave at 1500 W for 15 min, add 3 g of dopamine hydrochloride and 0.7 g of catalyst, heat it to 45 °C, stir and react for 3 h, centrifuge, wash, and dry to obtain polydopamine-modified polyacene;

[0060] The catalyst is a Tris-HCl solution with pH = 9;

[0061] S3. Preparation of Modified Carbon Black: Add 10 g of carbon black into 200 mL of ethanol, disperse it by ultrasonic wave at 1000 W for 15 min, add 2.5 g of silane coupling agent, heat it to 50 °C, stir and react for 2.5 h, centrifuge, wash, and dry to obtain modified carbon black;

[0062] The silane coupling agent is a mixture of KH570 and KH560 with a mass ratio of 4:6;

[0063] S4. Preparation of DOPO-Modified Carbon Black: Add 8 g of modified carbon black and 1.5 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide into 200 mL of tetrahydrofuran, stir and react for 4 h, centrifuge, wash, and dry to obtain DOPO-modified carbon black;

[0064] S5. Preparation of Antistatic and Flame Retardant Modifier: Add 10 g of polydopamine-modified polyacene and 4 g of DOPO-modified carbon black into 200 mL of acetonitrile, stir and react for 13 h, centrifuge, wash, and dry to obtain antistatic and flame retardant modifier;

[0065] S6. Preparation of Antistatic and Flame Retardant Material: Put 100 g of low-density polyethylene into a dryer for drying at a temperature of 120 °C. After naturally cooling to 70 °C, mix it evenly with 4.5 g of antistatic and flame retardant modifier, 0.7 g of plastic brightener OB, 1.5 g of methacryloyloxyethyltrimethylammonium chloride, 0.7 g of 2-hydroxy-4-n-octyldibenzophenone, and 3 g of talcum powder, and then put it into a foaming production line. The temperature of the foaming production line is divided into 11 zoning and temperature control zones. The temperature of zones 1-3 is 100 °C, the temperature of zones 4-8 is 190 °C, the temperature of the temperature control zone is 150 °C, the temperature of zones 9-11 is 180 °C, and the temperature of the die head discharging is 140 °C. The metering pump respectively feeds 1.2 g of n-butane and 0.7 g of food-grade monoglyceride to assist in foaming for 5 h, then discharge the material, and the winding speed can reach 1.15 m / s to obtain the antistatic and flame retardant material.

[0066] Example 4

[0067] Compared with Example 3, the difference is that the silane coupling agent is a single KH570.

[0068] Example 5

[0069] Compared with Example 3, the difference is that the silane coupling agent is a single KH560.

[0070] Comparative Example 1

[0071] Compared with Example 3, the difference lies in that step S2 is not carried out.

[0072] Specifically as follows:

[0073] S1. Preparation of polyacene: 1 mol of phenol and 1.1 mol of formaldehyde were mixed evenly, 6 mL of ammonia water was added, and the mixture was heated under reflux and stirred for reaction for 3 h. The pH value of the solution was adjusted to 5, and the reaction was continued for 3 h. Zinc chloride was added, and the addition amount was 1.5 wt% of the total mass of the system. It was heated to 70 °C and cured for 22 h. Under nitrogen protection, it was pyrolyzed at 1150 °C for 3 h, pulverized, and ball-milled for 1.5 h to obtain polyacene;

[0074] S2. Preparation of modified carbon black: 10 g of carbon black was added to 200 mL of ethanol, ultrasonically dispersed at 1000 W for 15 min, 2.5 g of silane coupling agent was added, heated to 50 °C, and stirred for reaction for 2.5 h. After centrifugation, washing, and drying, modified carbon black was obtained;

[0075] The silane coupling agent is a mixture of KH570 and KH560, and the mass ratio is 4:6;

[0076] S3. Preparation of DOPO-modified carbon black: 8 g of modified carbon black and 1.5 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide were added to 200 mL of tetrahydrofuran, stirred for reaction for 4 h, centrifuged, washed, and dried to obtain DOPO-modified carbon black;

[0077] S4. Preparation of antistatic and flame-retardant modifier: 10 g of polyacene and 4 g of DOPO-modified carbon black were added to 200 mL of acetonitrile, stirred and mixed for 13 h, centrifuged, washed, and dried to obtain an antistatic and flame-retardant modifier;

[0078] S5. Preparation of antistatic and flame-retardant material: 100 g of low-density polyethylene was dried in a dryer at a temperature of 120 °C. After natural cooling to 70 °C, it was mixed evenly with 4.5 g of antistatic and flame-retardant modifier, 0.7 g of plastic brightener OB, 1.5 g of methacryloyloxyethyl trimethyl ammonium chloride, 0.7 g of 2-hydroxy-4-n-octyldibenzophenone, and 3 g of talcum powder, and then entered the foaming production line. The temperature of the foaming production line was divided into 11 partition and temperature control zones. The temperature of zones 1-3 was 100 °C, zones 4-8 was 190 °C, the temperature control zone was 150 °C, zones 9-11 was 180 °C, and the die head discharge temperature was 140 °C. 1.2 g of n-butane and 0.7 g of food-grade monoglyceride were respectively introduced by metering pumps to assist foaming for 5 h, and then discharged. The winding speed could reach 1.15 m / s to obtain an antistatic and flame-retardant material.

[0079] Comparative Example 2

[0080] Compared with Example 3, the difference lies in that step S3 is not carried out.

[0081] Specifically as follows:

[0082] S1. Preparation of polyacene: Mix 1 mol of phenol and 1.1 mol of formaldehyde evenly, add 6 mL of ammonia water, heat under reflux and stir for reaction for 3 h, adjust the pH value of the solution to 5, continue heating and reacting for 3 h, add zinc chloride, and the addition amount is 1.5 wt% of the total mass of the system. Heat to 70 °C, cure for 22 h, pyrolyze at 1150 °C for 3 h under nitrogen protection, pulverize, and ball mill for 1.5 h to obtain polyacene;

[0083] S2. Preparation of polydopamine-modified polyacene: Add 10 g of polyacene to 200 mL of water, disperse by ultrasonic wave at 1500 W for 15 min, add 3 g of dopamine hydrochloride and 0.7 g of catalyst, heat to 45 °C, stir and react for 3 h, centrifuge, wash, and dry to obtain polydopamine-modified polyacene;

[0084] The catalyst is a Tris-HCl solution with pH = 9;

[0085] S3. Preparation of DOPO and carbon black mixture: Add 8 g of carbon black and 1.5 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to 200 mL of tetrahydrofuran, stir and react for 4 h, centrifuge, wash, and dry to obtain DOPO and carbon black mixture;

[0086] S4. Preparation of antistatic and flame retardant modifier: Add 10 g of polydopamine-modified polyacene and 4 g of DOPO and carbon black mixture to 200 mL of acetonitrile, stir and react for 13 h, centrifuge, wash, and dry to obtain antistatic and flame retardant modifier;

[0087] S5. Preparation of antistatic and flame retardant material: Put 100 g of low-density polyethylene into a dryer for drying at a temperature of 120 °C. After naturally cooling to 70 °C, mix it evenly with 4.5 g of antistatic and flame retardant modifier, 0.7 g of plastic brightener OB, 1.5 g of methacryloyloxyethyltrimethylammonium chloride, 0.7 g of 2-hydroxy-4-n-octyldibenzophenone, and 3 g of talc powder, and then enter the foaming production line. The temperature of the foaming production line is divided into 11 partition and temperature control zones. The temperature of zones 1-3 is 100 °C, the temperature of zones 4-8 is 190 °C, the temperature of the temperature control zone is 150 °C, the temperature of zones 9-11 is 180 °C, the temperature of the die head discharging is 140 °C. The metering pump respectively feeds 1.2 g of n-butane and 0.7 g of food-grade monoglyceride to assist foaming for 5 h, discharge the material, and the winding speed can reach 1.15 m / s to obtain the antistatic and flame retardant material.

[0088] Comparative Example 3

[0089] Compared with Example 3, the difference lies in that step S4 is not carried out.

[0090] The details are as follows:

[0091] S1. Preparation of polyacene: 1 mol of phenol and 1.1 mol of formaldehyde were mixed evenly, 6 mL of ammonia water was added, and the mixture was heated under reflux with stirring for 3 h. The pH value of the solution was adjusted to 5, and the reaction was continued by heating for 3 h. Zinc chloride was added, and the addition amount was 1.5 wt% of the total mass of the system. The mixture was heated to 70 °C and cured for 22 h. Under nitrogen protection, it was pyrolyzed at 1150 °C for 3 h, pulverized, and ball-milled for 1.5 h to obtain polyacene;

[0092] S2. Preparation of polydopamine-modified polyacene: 10 g of polyacene was added to 200 mL of water, ultrasonically dispersed at 1500 W for 15 min, 3 g of dopamine hydrochloride and 0.7 g of catalyst were added, the mixture was heated to 45 °C, and stirred for 3 h. After centrifugation, washing, and drying, polydopamine-modified polyacene was obtained;

[0093] The catalyst was a Tris-HCl solution with pH = 9;

[0094] S3. Preparation of modified carbon black: 10 g of carbon black was added to 200 mL of ethanol, ultrasonically dispersed at 1000 W for 15 min, 2.5 g of silane coupling agent was added, the mixture was heated to 50 °C, and stirred for 2.5 h. After centrifugation, washing, and drying, modified carbon black was obtained;

[0095] The silane coupling agent was a mixture of KH570 and KH560 with a mass ratio of 4:6;

[0096] S4. Preparation of antistatic and flame-retardant modifier: 10 g of polydopamine-modified polyacene and 4 g of modified carbon black were added to 200 mL of acetonitrile, stirred for 13 h, centrifuged, washed, and dried to obtain an antistatic and flame-retardant modifier;

[0097] S5. Preparation of antistatic and flame-retardant material: 100 g of low-density polyethylene was dried in a dryer at a temperature of 120 °C. After naturally cooling to 70 °C, it was mixed evenly with 4.5 g of antistatic and flame-retardant modifier, 0.7 g of plastic brightener OB, 1.5 g of methacryloyloxyethyltrimethylammonium chloride, 0.7 g of 2-hydroxy-4-n-octyldibenzophenone, and 3 g of talc powder, and then fed into a foaming production line. The temperature of the foaming production line was divided into 11 zoning and temperature control zones. The temperature in zones 1-3 was 100 °C, in zones 4-8 was 190 °C, the temperature control zone was 150 °C, in zones 9-11 was 180 °C, and the die head discharge temperature was 140 °C. 1.2 g of n-butane and 0.7 g of food-grade monoglyceride were respectively fed by metering pumps to assist in foaming for 5 h, and then discharged. The winding speed could reach 1.15 m / s to obtain an antistatic and flame-retardant material.

[0098] Comparative Example 4

[0099] Compared with Example 3, the difference is that DOPO-modified carbon black was not added in step S5.

[0100] The details are as follows:

[0101] S1. Preparation of polyacene: 1 mol of phenol and 1.1 mol of formaldehyde were mixed evenly, 6 mL of ammonia water was added, and the mixture was heated under reflux with stirring for 3 h. The pH value of the solution was adjusted to 5, and the reaction was continued by heating for 3 h. Zinc chloride was added, and the addition amount was 1.5 wt% of the total mass of the system. The mixture was heated to 70 °C and cured for 22 h. Under nitrogen protection, it was pyrolyzed at 1150 °C for 3 h, pulverized, and ball-milled for 1.5 h to obtain polyacene;

[0102] S2. Preparation of polydopamine-modified polyacene: 10 g of polyacene was added to 200 mL of water, and ultrasonic dispersion was carried out at 1500 W for 15 min. 3 g of dopamine hydrochloride and 0.7 g of catalyst were added, and the mixture was heated to 45 °C and stirred for 3 h. After centrifugation, washing, and drying, polydopamine-modified polyacene was obtained;

[0103] The catalyst is a Tris-HCl solution with pH = 9;

[0104] S3. Preparation of antistatic and flame-retardant modifier: The polydopamine-modified polyacene was used as the antistatic and flame-retardant modifier;

[0105] S4. Preparation of antistatic and flame-retardant material: 100 g of low-density polyethylene was put into a dryer for drying at a temperature of 120 °C. After naturally cooling to 70 °C, it was mixed evenly with 4.5 g of antistatic and flame-retardant modifier, 0.7 g of plastic brightener OB, 1.5 g of methacryloyloxyethyltrimethylammonium chloride, 0.7 g of 2-hydroxy-4-n-octyldibenzophenone, and 3 g of talcum powder, and then entered the foaming production line. The temperature of the foaming production line was divided into 11 partition and temperature adjustment zones. The temperature of zones 1 - 3 was 100 °C, zones 4 - 8 was 190 °C, the temperature adjustment zone was 150 °C, zones 9 - 11 was 180 °C, and the die head discharge temperature was 140 °C. 1.2 g of n-butane and 0.7 g of food-grade monoglyceride were respectively fed by metering pumps to assist foaming for 5 h, and then discharged. The winding speed could reach 1.15 m / s to obtain the antistatic and flame-retardant material.

[0106] Comparative Example 5

[0107] Compared with Example 3, the difference is that polydopamine-modified polyacene was not added in step S5.

[0108] The details are as follows:

[0109] S1. Preparation of modified carbon black: 10 g of carbon black was added to 200 mL of ethanol, and ultrasonic dispersion was carried out at 1000 W for 15 min. 2.5 g of silane coupling agent was added, and the mixture was heated to 50 °C and stirred for 2.5 h. After centrifugation, washing, and drying, modified carbon black was obtained;

[0110] The silane coupling agent is a mixture of KH570 and KH560, and the mass ratio is 4:6;

[0111] S2. Preparation of DOPO-modified carbon black: Add 8 g of modified carbon black and 1.5 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to 200 mL of tetrahydrofuran, stir and react for 4 h, centrifuge, wash, and dry to obtain DOPO-modified carbon black;

[0112] S3. Preparation of antistatic and flame-retardant modifier: Use DOPO-modified carbon black as the antistatic and flame-retardant modifier;

[0113] S4. Preparation of antistatic and flame-retardant material: Put 100 g of low-density polyethylene into a dryer and dry it at a temperature of 120 °C. After naturally cooling to 70 °C, mix it evenly with 4.5 g of antistatic and flame-retardant modifier, 0.7 g of plastic brightener OB, 1.5 g of methacryloyloxyethyltrimethylammonium chloride, 0.7 g of 2-hydroxy-4-n-octyldibenzophenone, and 3 g of talc powder, and then enter the foaming production line. The temperature of the foaming production line is divided into 11 zoning and temperature control zones. The temperature in zones 1-3 is 100 °C, in zones 4-8 is 190 °C, the temperature control zone is 150 °C, in zones 9-11 is 180 °C, and the die head discharge temperature is 140 °C. The metering pump respectively feeds 1.2 g of n-butane and 0.7 g of food-grade monoglyceride to assist in foaming for 5 h, then discharge the material, and the winding speed can reach 1.15 m / s to obtain the antistatic and flame-retardant material.

[0114] Test Example 1

[0115] Conduct a flame retardancy test on the antistatic and flame-retardant materials prepared in Examples 1-5 and Comparative Examples 1-5, and the results are shown in Table 1.

[0116] Determine the oxygen index of the antistatic and flame-retardant material in a JF-3 type oxygen index meter, and the specimen specifications are [length 120 mm, width (6.5 ± 0.5) mm, thickness (3.0 ± 0.5) mm].

[0117] The flame retardancy grade is tested according to the UL-94 standard.

[0118] Table 1

[0119] Group Limiting oxygen index (%) Flame retardancy rating (0.8 mm) Example 1 33.6 V-0 Example 2 34.1 V-0 Example 3 34.5 V-0 Example 4 32.9 V-0 Example 5 29.7 V-0 Comparative Example 1 31.0 V-0 Comparative Example 2 26.6 V-1 Comparative Example 3 25.4 V-1 Comparative Example 4 22.2 V-2 Comparative Example 5 23.1 V-2

[0120] As can be seen from the above table, the antistatic and flame-retardant materials prepared in Examples 1-3 of the present invention have good flame retardancy.

[0121] Test Example 2

[0122] Conduct a surface resistivity test on the antistatic and flame-retardant materials prepared in Examples 1-5 and Comparative Examples 1-5 according to the method in ASTM D-257, and the results are shown in Table 2.

[0123] Table 2

[0124] Group Volume resistivity (Ω·m) Example 1 <![CDATA[7.14×10 5 > Example 2 <![CDATA[7.29×10 5 > Example 3 <![CDATA[7.02×10 5 > Example 4 <![CDATA[2.95×10 6 > Example 5 <![CDATA[9.28×10 5 > Comparative Example 1 <![CDATA[8.55×10 6 > Comparative Example 2 <![CDATA[1.58×10 7 > Comparative Example 3 <![CDATA[1.83×10 6 > Comparative Example 4 <![CDATA[9.71×10 7 > Comparative Example 5 <![CDATA[4.82×10 8 >

[0125] As can be seen from the above table, the antistatic and flame-retardant materials prepared in Examples 1-3 of the present invention have good antistatic performance.

[0126] Test Example 3

[0127] The antistatic and flame-retardant materials prepared in Examples 1-5 and Comparative Examples 1-5 were tested for tensile strength and elongation at break of the specimens according to the provisions of ISO 527-1 / 2:2019. The specimen size was 50 mm × 50 mm × 5 mm. The results are shown in Table 3.

[0128] Table 3

[0129] Group Tensile strength (MPa) Elongation at break (%) Example 1 0.85 125 Example 2 0.87 129 Example 3 0.87 132 Example 4 0.78 99 Example 5 0.80 104 Comparative Example 1 0.72 75 Comparative Example 2 0.70 67 Comparative Example 3 0.82 118 Comparative Example 4 0.67 52 Comparative Example 5 0.60 40

[0130] As can be seen from the above table, the antistatic and flame-retardant materials prepared in Examples 1-3 of the present invention have good mechanical properties.

[0131] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an antistatic flame retardant material, characterized in that: The polyphenylene is modified by polydopamine, and reacted with carbon black modified by a silane coupling agent after a DOPO reaction to obtain an antistatic flame retardant modifier, which is evenly mixed with low-density polyethylene, a brightener, an antibacterial agent, a stabilizer, and talcum powder and then fed into a foaming production line, where a butane foaming agent and food-grade monoglyceride are introduced to assist in foaming, and the material is discharged to obtain an antistatic flame retardant material.

2. The preparation method according to claim 1, characterized in that: The following steps are involved: S1. Preparation of polyphenylene: phenol and formaldehyde are mixed evenly, ammonia water is added, heated to reflux and stirred for reaction, pH value of the solution is adjusted, heating reaction is continued, zinc chloride is added, heating and curing is performed, thermal cracking is performed, crushing is performed, and ball milling is performed to obtain polyphenylene; S2. Preparation of polydopamine-modified polyphenylene: adding polyphenylene to water, uniformly dispersing by ultrasonication, adding dopamine hydrochloride and a catalyst, heating and stirring to react, centrifuging, washing, and drying to obtain polydopamine-modified polyphenylene; S3. Preparation of modified carbon black: adding carbon black to ethanol, uniformly dispersing by ultrasonication, adding a silane coupling agent, heating and stirring to react, centrifuging, washing, and drying to obtain modified carbon black; S4. Preparation of DOPO modified carbon black: adding modified carbon black and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide into tetrahydrofuran, stirring for reaction, centrifuging, washing, and drying to obtain DOPO modified carbon black; S5. Preparation of an antistatic flame retardant modifier: adding polydopamine-modified polyphenylene and DOPO-modified carbon black to acetonitrile, stirring the reaction, centrifuging, washing, and drying to obtain an antistatic flame retardant modifier; S6. Preparation of anti-static flame retardant materials: dry the low-density polyethylene, mix it evenly with the anti-static flame retardant modifier, brightener, antibacterial agent, stabilizer and talcum powder, and then feed it into the foaming production line. Add butane foaming agent and food-grade monoglyceride to assist foaming, discharge the material, and obtain the anti-static flame retardant material.

3. The preparation method according to claim 2, characterized in that: The molar ratio of phenol to formaldehyde in step S1 is 1:1-1.2, the heating reflux stirring reaction time is 2-4 hours, the pH value of the solution is adjusted to 4-6, the heating reaction time is continued for 2-4 hours, the amount of zinc chloride added is 1-2wt% of the total mass of the system, the heating curing temperature is 65-75°C, the time is 20-24 hours, the thermal cracking temperature is 1000-1200°C, the time is 2-4 hours, and the ball milling time is 1-2 hours.

4. The preparation method according to claim 2, characterized in that: In step S2, the mass ratio of the polyphenylene, dopamine hydrochloride and catalyst is 10:2-4:0.5-1, the temperature of the heating and stirring reaction is 40-50° C., and the time is 2-4 hours; the catalyst is a Tris-HCl solution with a pH of 8.5-9.

5.

5. The preparation method according to claim 2, characterized in that: In step S3, the mass ratio of carbon black to silane coupling agent is 10:2-3, the silane coupling agent is a mixture of KH570 and KH560, the mass ratio is 3-5:6, the temperature of the heating and stirring reaction is 45-55°C, and the time is 2-3h.

6. The preparation method according to claim 2, characterized in that: In step S4, the mass ratio of the modified carbon black to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 7-10:1-2, and the stirring reaction time is 3-5h.

7. The preparation method according to claim 2, characterized in that: In step S5, the mass ratio of the polydopamine-modified polyphenylene to the DOPO-modified carbon black is 10:3-5, and the stirring reaction time is 12-15 hours.

8. The preparation method according to claim 2, characterized in that: The mass ratio of the antistatic flame retardant modifier, low-density polyethylene, brightener, antibacterial agent, stabilizer, talc, butane foaming agent and monoglyceride in step S6 is 4-5:100:0.5-1:1-2:0.5-1:2-4:1-1.5:0.5-1, the drying treatment temperature is 110-130 ° C, the time is 1-2h, the temperature of the foaming production line is divided into 11 zones and temperature adjustment zones, 1-3 zones are 85-110 ° C, 4-8 zones are 180-200 ° C, the temperature adjustment zone is 140-160 ° C, 9-11 zones are 170-190 ° C, the die discharge is 150-130 ° C, and the winding speed is 1-1.3 m / s.

9. An antistatic and flame retardant material obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the antistatic and flame retardant material according to claim 9 in the preparation of plastics for coal mines.