A flame-retardant TPE magnetic adsorption material and its preparation method

Abstract

This application relates to the field of TPE materials, and specifically discloses a flame-retardant TPE magnetic material and a preparation method thereof. A flame-retardant TPE magnetic material is prepared from the following raw materials in parts by weight: 5-20 parts of SEBS, 60-80 parts of pretreated magnetic powder, 10-20 parts of flame retardant, 5-15 parts of plasticizer, 4-8 parts of compatibilizer, 2-6 parts of tackifier, 1-3 parts of lubricant, and 0.2-1 part of antioxidant; the pretreated magnetic powder is prepared by modifying magnetic powder, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tetraethylene glycol diacrylate, coupling agent and alcohol solvent; Preparation method: Mix SEBS, flame retardant, plasticizer, compatibilizer, lubricant and antioxidant, then add pretreated magnetic powder and mix well, extrude, cool and granulate. The flame-retardant TPE magnetic material of this application has good flame retardancy and flexibility, is applied to magnetic data cables, has good magnetic absorption and storage performance, and is not easy to crack after long-term winding and use.

Description

Technical Field

[0001] The present application relates to the field of TPE materials, and more specifically, it relates to a flame-retardant TPE magnetic attraction material and a preparation method thereof. Background Art

[0002] With the continuous development of electronic technology, magnetic materials are widely used in the field of consumer electronic products. Due to the good magnetic attraction effect of magnetic materials, they can be applied to magnetic attraction charging, magnetic attraction data lines, and so on.

[0003] TPE material is a thermoplastic elastomer material that combines the advantages of thermoplastic plastics and elastic rubbers, and has high strength and high resilience performance; TPE material is safe and non-toxic to the human body, suitable for environments in long-term contact with the skin, and the material can be processed by injection molding and other processing technologies to prepare products with different structures and shapes. Therefore, currently, TPE is usually compounded with magnetic materials to prepare TPE magnetic materials.

[0004] In order to improve the flame-retardant performance and magnetic attraction performance of TPE materials, currently, generally, flame retardants and magnetic powders are added to TPE materials. Due to the large filling amounts of flame retardants and magnetic powders, the flexibility of the prepared TPE magnetic attraction material is reduced, cracking is likely to occur, and at the same time, the flame retardancy of the prepared TPE magnetic material is also reduced. Summary of the Invention

[0005] In order to solve the problems that the existing TPE magnetic attraction materials are prone to cracking and have relatively low flame retardancy, the present application provides a flame-retardant TPE magnetic attraction material and a preparation method thereof.

[0006] In the first aspect, the present application provides a flame-retardant TPE magnetic attraction material, adopting the following technical scheme:

[0007] A flame-retardant TPE magnetic attraction material is prepared from the following raw materials in parts by weight:

[0008] SEBS 5 - 20 parts

[0009] Pretreated magnetic powder 60 - 80 parts

[0010] Flame retardant 10 - 20 parts

[0011] Plasticizer 5 - 15 parts

[0012] Compatibilizer 4 - 8 parts

[0013] Adhesive enhancer 2 - 6 parts

[0014] Lubricant 1 - 3 parts

[0015] Antioxidant 0.2 - 1 part;

[0016] The pretreated magnetic powder is prepared by modifying magnetic powder, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tetraethylene glycol diacrylate, coupling agent and alcohol solvent.

[0017] By adopting the above technical solution, in this application, SEBS is used as the TPE material. SEBS is a linear triblock copolymer with polystyrene as the end segment and ethylene-butene copolymer obtained by hydrogenating polybutadiene as the middle elastic block. SEBS does not contain unsaturated double bonds, so it has good flexibility, elasticity and aging resistance. SEBS can play a good bonding role for the pretreated magnetic powder and the flame retardant. The compatibilizer and tackifier can play a good synergistic effect, further improving the dispersion uniformity and bonding stability of SEBS, the pretreated magnetic powder and the flame retardant. Since the fillers of the pretreated magnetic powder and the flame retardant are relatively large, in this application, magnetic powder is modified with acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tetraethylene glycol diacrylate, coupling agent and alcohol solvent to prepare the pretreated magnetic powder of this application. The prepared pretreated magnetic powder has good flexibility and dispersion uniformity, can be evenly dispersed into SEBS, forming a uniform and dense elastomer molecular structure, and can also improve the dispersion effect of the flame retardant in SEBS. The flame-retardant TPE magnetic attraction material prepared in this way has relatively moderate hardness, good flame retardancy, flexibility and mechanical properties. When applied to magnetic attraction data cables, it has good magnetic absorption and storage performance, and is not prone to cracking after long-term coiling and bending.

[0018] Preferably, the pretreated magnetic powder is prepared from the following raw materials in parts by weight:

[0019] 80-120 parts of magnetic powder

[0020] 4-6 parts of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer

[0021] 1-3 parts of tetraethylene glycol diacrylate

[0022] 3-8 parts of coupling agent

[0023] 20-50 parts of alcohol solvent;

[0024] The magnetic powder is neodymium iron boron magnetic powder, the coupling agent is titanate coupling agent and / or silane coupling agent, and the alcohol solvent is an ethanol aqueous solution with a concentration of 60-90wt%.

[0025] By adopting the above technical solution, the above coupling agent can graft with magnetic powder in an alcohol solvent, reduce the surface energy of the magnetic powder, and improve the dispersion performance of the magnetic powder. The magnetic powder after grafting with the coupling agent is further dispersed in the copolymer of acrylic acid-2-acrylamido-2-methylpropanesulfonic acid and tetraethylene glycol diacrylate. The copolymer of acrylic acid-2-acrylamido-2-methylpropanesulfonic acid and tetraethylene glycol diacrylate can form a uniform and soft coating film on the surface of the silane-grafted magnetic powder. The prepared pretreated magnetic powder can be uniformly and stably dispersed in SEBS, and at the same time, it can also improve the dispersion and compatibility of the flame retardant in SEBS, so that during the processing and molding process, the pretreated magnetic powder and the flame retardant can be uniformly dispersed and intertwined in the elastomeric structure of SEBS, thereby improving the flame retardancy, flexibility and magnetic properties of the prepared flame-retardant TPE magnetic material.

[0026] Preferably, the coupling agent is composed of bis(dioctyloxy pyrophosphatooxy)ethylene titanate and 3-(methacryloyloxy)propyltrimethoxysilane with a weight ratio of 1:(1-3).

[0027] By adopting the above technical solution, in this application, bis(dioctyloxy pyrophosphatooxy)ethylene titanate is used as the titanate coupling agent, and 3-(methacryloyloxy)propyltrimethoxysilane is used as the silane coupling agent. The two are compounded in a better ratio, which can produce a better synergistic effect, can stably graft with the magnetic powder on the surface in an alcohol solvent, make the magnetic powder particles evenly dispersed and the distance between the magnetic powder particles enlarged, and then can improve the formation of a uniform coating film of the copolymer of acrylic acid-2-acrylamido-2-methylpropanesulfonic acid and tetraethylene glycol diacrylate on the surface of the magnetic powder, improve the coating efficiency, further improve the performance stability of the prepared pretreated magnetic powder, reduce the magnetic loss of the magnetic powder during the subsequent processing and molding process, and improve the flame retardancy, flexibility and magnetic properties of the flame-retardant TPE magnetic material prepared by magnetic attraction.

[0028] Preferably, the pretreated magnetic powder is prepared by the following steps:

[0029] A1. Add the coupling agent to an alcohol solvent, then add magnetic powder, heat up to 45-55 °C, stir and react to obtain a magnetic powder dispersion;

[0030] A2. Add the copolymer of acrylic acid-2-acrylamido-2-methylpropanesulfonic acid and tetraethylene glycol diacrylate to the magnetic powder dispersion, heat up to 65-75 °C, stir for 1-2 h, filter and dry to obtain the pretreated magnetic powder.

[0031] By adopting the above technical solution, first, in an alcohol solvent, a coupling agent is used to modify the surface of the magnetic powder, reduce the surface energy of the magnetic powder, and improve the dispersion uniformity of the magnetic powder. Then, at a preferable temperature, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer and tetraethylene glycol diacrylate are uniformly adhered to the surface of the magnetic powder. Subsequently, filtration and drying are carried out to form a uniform and soft coating film on the surface of the magnetic powder, and thus the pretreated magnetic powder is obtained.

[0032] Preferably, the flame retardant is composed of decabromodiphenylethane and antimony trioxide with a weight ratio of 1:(2 - 4).

[0033] By adopting the above technical solution, decabromodiphenylethane and antimony trioxide with a preferable dosage ratio have a good synergistic effect, and can form a carbon layer under high-temperature conditions. This carbon layer can not only play a flame-retardant role but also play an endothermic role, thereby improving the flame-retardant performance of the prepared flame-retardant TPE magnetic attraction material.

[0034] Preferably, the compatibilizer is maleic anhydride grafted SEBS and / or maleic anhydride grafted PP.

[0035] By adopting the above technical solution, the above compatibilizer has good toughness and compatibility, and can improve the mixing uniformity among the pretreated magnetic powder, TPE, and tackifier.

[0036] Preferably, the tackifier is composed of ethylene acrylic acid copolymer and pentaerythritol ester of hydrogenated rosin with a weight ratio of (0.5 - 1.5):1.

[0037] By adopting the above technical solution, the ethylene acrylic acid copolymer has good flexibility and adhesiveness, and is compounded with pentaerythritol ester of hydrogenated rosin at a preferable dosage ratio. The two have a good synergistic effect, can improve the softness and mechanical properties of the prepared flame-retardant TPE magnetic attraction material, and can play a good synergistic effect with the compatibilizer to further improve the anti-cracking performance of the flame-retardant TPE magnetic attraction material.

[0038] Preferably, the plasticizer is one or more of white oil, epoxy soybean oil, and tributyl citrate, the lubricant is one or more of polyethylene wax, ethylene bisstearamide, and zinc stearate, and the antioxidant is a hindered phenol antioxidant and / or a phosphite antioxidant.

[0039] By adopting the above technical solution, the above plasticizer can improve the dispersion performance of TPE, and improve the processing stability and flexibility of the flame-retardant TPE magnetic attraction material; the lubricant can play a role in improving the mixing uniformity of each component, reducing the frictional force between materials, and further improving the processing stability; the antioxidant can improve the aging resistance of the prepared flame-retardant TPE magnetic attraction material and extend the service life.

[0040] Second aspect, the present application provides a preparation method of a flame-retardant TPE magnetic material, adopting the following technical solution: A preparation method of a flame-retardant TPE magnetic material, comprising the following steps:

[0041] S1. Add SEBS, flame retardant, plasticizer, compatibilizer, tackifier, lubricant, antioxidant into a mixing device, mix and knead to obtain mixture A;

[0042] S2. Add pretreated magnetic powder into mixture A, mix evenly, add it into an extrusion device for extrusion, cool and pelletize to obtain the flame-retardant TPE magnetic material.

[0043] By adopting the above technical solution, first mix and knead SEBS, flame retardant, plasticizer, compatibilizer, tackifier, lubricant and antioxidant evenly, so that each material forms a uniform mixing system, and then add pretreated magnetic powder for dispersion, so that the pretreated magnetic powder is evenly dispersed, improving the uniform adhesion to the pretreated magnetic powder, and then extrude and pelletize to prepare the flame-retardant TPE magnetic material.

[0044] Preferably, the mixing and kneading temperature in step S1 is 150 - 170 °C, and the extrusion temperature in step S2 is 190 - 220 °C.

[0045] By adopting the above technical solution, a better mixing and kneading temperature can make each material mix evenly, and a better extrusion temperature can make each material be stably compatible, thereby preparing a flame-retardant TPE magnetic material with better structural uniformity and compactness.

[0046] To sum up, the present application has the following beneficial effects:

[0047] 1. For the flame-retardant TPE magnetic material of the present application, SEBS is used as the TPE material to disperse and bond the pretreated magnetic powder and the flame retardant. In order to improve the dispersion uniformity of the flame retardant and the pretreated magnetic powder in SEBS, the pretreated magnetic powder is prepared by modifying magnetic powder with acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, tetraethylene glycol diacrylate, coupling agent and alcohol solvent. The prepared pretreated magnetic powder can be evenly dispersed in SEBS, and at the same time, it can also improve the dispersibility and compatibility of the flame retardant in SEBS. The compatibilizer and the tackifier can play a better synergistic effect, further improving the dispersion uniformity and bonding stability of SEBS, pretreated magnetic powder and flame retardant. The prepared flame-retardant TPE magnetic material has good flame retardancy, flexibility, mechanical properties and magnetic properties, and has good magnetic absorption and storage performance when applied to magnetic data cables, and is not prone to cracking after long-term coiling and bending.

[0048] 2. Using bis(dioctyloxy pyrophosphoryloxy) ethylene titanate with a relatively optimal dosage ratio as the titanate coupling agent and 3-(methacryloyloxy)propyltrimethoxysilane as the silane coupling agent, the two exhibit good synergistic effects, enabling the magnetic powder particles to be uniformly dispersed and the distance between the magnetic powder particles to be enlarged. Furthermore, the coating efficiency of the acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer and tetraethylene glycol diacrylate on the magnetic powder can be improved, the magnetic loss during the subsequent processing and molding of the magnetic powder can be reduced, and the flame retardancy, flexibility, and magnetic properties of the flame-retardant TPE magnetic material prepared by magnetic attraction can be enhanced.

[0049] 3. Using ethylene acrylic acid copolymer and pentaerythritol ester of hydrogenated rosin in relatively optimal proportions as tackifiers can improve the softness and mechanical properties of the prepared flame-retardant TPE magnetic material. At the same time, it can have a good synergistic effect with the compatibilizer, further enhancing the anti-cracking performance of the flame-retardant TPE magnetic material. Detailed implementation manners

[0050] The following further elaborates on this application in conjunction with examples.

[0051] The following are the sources and specifications of some raw materials for this application. The raw materials used in the preparation examples and implementation examples of this application can all be obtained commercially, including but not limited to the raw materials of the following models and manufacturers. Raw materials with the same performance can all be used:

[0052] 1. SEBS: Taiwan Synthetic Rubber Corporation, China, model 6151;

[0053] 2. Magnetic powder: Magnequench (Tianjin) Co., Ltd., China, MQP-A-10179 magnetic powder;

[0054] 3. Acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer: Kemike, CAS number: 40623-75-4, solid content 30%; 4. Tetraethylene glycol diacrylate: content 90%, CAS number 17831-71-9;

[0055] 5. Bis(dioctyloxy pyrophosphoryloxy) ethylene titanate: HY-311W, CAS number: 65467-75-6;

[0056] 6. Maleic anhydride grafted SEBS: Taiwan Synthetic Rubber Corporation, China, model 7126;

[0057] 7. Maleic anhydride grafted PP: Mitsui Chemicals NF108;

[0058] 8. Ethylene acrylic acid copolymer: DuPont 2116AC;

[0059] 9. Pentaerythritol ester of hydrogenated rosin: CAS number: 64365-17-9, content 99%;

[0060] 10. Epoxidized soybean oil: CAS No. 8013-07-8, epoxy value greater than 6.3%, molecular weight 1000;

[0061] 11. Polyethylene wax: Honeywell, AC-629A.

[0062] Preparation examples of pretreated magnetic powder

[0063] Preparation example 1

[0064] Preparation example 1 discloses a pretreated magnetic powder, which is prepared by the following steps:

[0065] A1. Add 0.3 kg of isopropyl triisostearoyl titanate as a titanate coupling agent to 2 kg of an ethanol aqueous solution with a concentration of 60 wt%, then add 8 kg of neodymium iron boron magnetic powder, heat up to 45 °C, and stir and react for 30 min to obtain a magnetic powder dispersion;

[0066] A2. Add 0.4 kg of acrylic acid-2-acrylamido-2-methylpropanesulfonic acid copolymer and 0.3 kg of tetraethylene glycol diacrylate to the magnetic powder dispersion, heat up to 65 °C, stir for 1 h, filter, and then dry at 70 °C for 40 min to obtain the pretreated magnetic powder.

[0067] Preparation examples 2-3

[0068] The differences between preparation examples 2-3 and preparation example 1 are that the raw material dosages and preparation conditions are different. See Table 1 below for details.

[0069] Table 1 Raw material dosages and preparation conditions of preparation examples 1-3

[0070]

[0071] Preparation example 4

[0072] The difference between preparation example 4 and preparation example 1 is that the coupling agent is different. The coupling agent in preparation example 4 is composed of bis(dioctyloxy pyrophosphatoxy)ethylene titanate and 3-(methacryloyloxy)propyltrimethoxysilane with a weight ratio of 1:1, and the others are the same as preparation example 1.

[0073] Preparation example 5

[0074] The difference between preparation example 5 and preparation example 4 is that the coupling agent is composed of bis(dioctyloxy pyrophosphatoxy)ethylene titanate and 3-(methacryloyloxy)propyltrimethoxysilane with a weight ratio of 1:3, and the others are the same as preparation example 4.

[0075] Preparation comparative example 1

[0076] The difference between Preparation Comparative Example 1 and Preparation Example 1 is that the acrylic acid-2-acrylamido-2-methylpropanesulfonic acid copolymer is replaced with tetraethylene glycol diacrylate in equal amounts, and the others are the same as Preparation Example 1.

[0077] Preparation Comparative Example 2

[0078] The difference between Preparation Comparative Example 2 and Preparation Example 1 is that the tetraethylene glycol diacrylate is replaced with glycidyl methacrylate in equal amounts, and the others are the same as Preparation Example 1.

[0079] Preparation Comparative Example 3

[0080] The difference between Preparation Comparative Example 3 and Preparation Example 1 is that 0.3 kg of triisostearoyl titanate is added to 2 kg of an ethanol aqueous solution with a concentration of 60 wt%, then 8 kg of neodymium iron boron magnetic powder is added, the temperature is raised to 45 °C, and the mixture is stirred and reacted for 30 min to obtain a magnetic powder dispersion liquid, which is then filtered and dried at 70 °C for 40 min to obtain a pretreated magnetic powder.

[0081] Examples

[0082] Example 1

[0083] Example 1 discloses a flame-retardant TPE magnetic material, which is prepared by the following steps:

[0084] S1. Add 0.5 kg of SEBS, 1 kg of a flame retardant composed of decabromodiphenylethane and antimony trioxide with a weight ratio of 1:2, 0.5 kg of 26# white oil as a plasticizer, 0.4 kg of a compatibilizer composed of maleic anhydride grafted SEBS and maleic anhydride grafted PP with a weight ratio of 3:1, 0.2 kg of ethylene acrylic acid copolymer as a tackifier, 0.1 kg of polyethylene wax as a lubricant, and 0.06 kg of an antioxidant composed of antioxidant 1010 and antioxidant 168 with a weight ratio of 1:2 into a mixer, and mix at 150 °C for 30 min to mix evenly to obtain mixture A;

[0085] S2. Add 6 kg of the pretreated magnetic powder prepared in Preparation Example 1 to mixture A, mix for 40 min to mix evenly, add it to a twin-screw extruder, and control the extrusion temperature as follows under the condition that the screw speed is 300 r / min: the temperature of zone 1 is 190 °C, the temperature of zone 2 is 195 °C, the temperature of zone 3 is 200 °C, the temperature of zone 4 is 210 °C, the temperature of zone 5 is 205 °C, and the die head temperature is 195 °C, and perform extrusion, water cooling, and granulation to obtain a flame-retardant TPE magnetic material.

[0086] Examples 2 - 3

[0087] Example 2-3 is different from Example 1 in that the raw material dosages and preparation conditions are different, and the sources of the pretreated magnetic powder are also different. See Table 2 below for details.

[0088] Table 2 Raw material dosages, preparation conditions and sources of pretreated magnetic powder for Examples 1-3

[0089]

[0090]

[0091] Example 4

[0092] Example 4 is different from Example 1 in that the pretreated magnetic powder is from Preparation Example 4, and the others are the same as Example 1.

[0093] Example 5

[0094] Example 5 is different from Example 1 in that the pretreated magnetic powder is from Preparation Example 5, and the others are the same as Example 1.

[0095] Example 6

[0096] Example 6 is different from Example 4 in that the tackifier is different. The tackifier in Example 6 consists of ethylene acrylic acid copolymer and pentaerythritol ester of hydrogenated rosin with a weight ratio of 0.5:1, and the others are the same as Example 4.

[0097] Example 7

[0098] Example 7 is different from Example 6 in that the tackifier in Example 7 consists of ethylene acrylic acid copolymer and pentaerythritol ester of hydrogenated rosin with a weight ratio of 1.5:1, and the others are the same as Example 6.

[0099] Comparative Example

[0100] Comparative Example 1

[0101] Comparative Example 1 is different from Example 1 in that the pretreated magnetic powder is from Preparation of Comparative Example 1, and the others are the same as Example 1.

[0102] Comparative Example 2

[0103] Comparative Example 2 is different from Example 1 in that the pretreated magnetic powder is from Preparation of Comparative Example 2, and the others are the same as Example 1.

[0104] Comparative Example 3

[0105] Comparative Example 3 is different from Example 1 in that the pretreated magnetic powder is from Preparation of Comparative Example 3, and the others are the same as Example 1.

[0106] Comparative Example 4

[0107] The difference between Comparative Example 4 and Example 1 is that the pre-treated magnetic powder is replaced with commercially available neodymium iron boron magnetic powder in equal amounts, and the others are the same as in Example 1.

[0108] Comparative Example 5

[0109] The difference between Comparative Example 5 and Example 1 is that the tackifier is replaced with a compatibilizer in equal amounts, and the others are the same as in Example 1.

[0110] Performance detection test The following performance tests were carried out on the flame-retardant TPE magnetic adsorption materials prepared in Examples 1-7 and Comparative Examples 1-5:

[0111] 1. Flame retardancy test:

[0112] Referring to Test Method B in GB / T 10707-2008: the test method in the vertical burning method, the flame retardancy grade of the flame-retardant TPE magnetic adsorption material was tested, which is divided into FV-0, FV-1 and FV-2, and the test was carried out and recorded;

[0113] 2. Hardness test:

[0114] Referring to the test method in GB / T 531.1-2008, the hardness (unit: shore A) of the flame-retardant TPE magnetic adsorption material was tested, and the test results were tested and recorded;

[0115] 3. Elongation at break test:

[0116] Referring to Test Method A in ASTM D412: the test method for straight strip and dumbbell specimens, the elongation at break (unit: %) of the flame-retardant TPE magnetic adsorption material was tested, and the test results were tested and recorded;

[0117] 4. Surface magnetic field strength test:

[0118] The flame-retardant TPE magnetic adsorption material was injection-molded into a test piece with a thickness of 1 mm, and a gaussmeter was used to test the magnetic field strength (unit: Gs) on the surface of the test piece, and the test results were tested and recorded;

[0119] The following are the performance test data of the flame-retardant TPE magnetic adsorption materials prepared in Examples 1-7 and Comparative Examples 1-5. For details, see Table 3 below.

[0120] Table 3 Performance test data table of flame-retardant TPE magnetic adsorption materials prepared in Examples 1-7 and Comparative Examples 1-5

[0121]

[0122]

[0123] Combined with Examples 1-3, Examples 4-5 and Comparative Examples 1-4 and Table 3, it can be concluded that by using the coupling agent, solvent, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer and tetraethylene glycol diacrylate of the present application to pretreat the magnetic powder, the prepared pretreated magnetic powder is applied to the flame-retardant TPE magnetic attraction material of the present application, which has good dispersion and mixing stability, can improve the flexibility of the prepared flame-retardant TPE magnetic attraction material, and reduce the occurrence of cracking; and in Examples 4-5, bis(dioctyloxy pyrophosphoryloxy)ethylene titanate and 3-(methacryloyloxy)propyltrimethoxysilane in a preferred weight ratio are further used as coupling agents, which can further improve the flexibility and anti-cracking performance of the prepared flame-retardant TPE magnetic attraction material. Perhaps because the bis(dioctyloxy pyrophosphoryloxy)ethylene titanate and 3-(methacryloyloxy)propyltrimethoxysilane in the preferred dosage ratio can stably graft with the magnetic powder, improve the coating performance of the acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer and tetraethylene glycol diacrylate on the magnetic powder, and then improve the mixing uniformity of the prepared pretreated magnetic powder and TPE; in Comparative Examples 1-3, the pretreated magnetic powder of the present application is not used, and in Comparative Example 4, commercially available magnetic powder is used. The flexibility and mechanical properties of the prepared flame-retardant TPE magnetic attraction material are both reduced, and the surface magnetic attraction performance is also reduced. Perhaps because the dispersion performance of the commercially available magnetic powder in TPE is low, making it difficult for the magnetic powder to be bonded and dispersed, resulting in a reduction in the mechanical properties of the material; the flame retardancy in Comparative Examples 3-4 is also reduced. Perhaps because the pretreated magnetic powder of the present application is not used, making it difficult for the flame retardant to be evenly dispersed in the TPE system, thereby reducing the flame retardancy of the prepared flame-retardant TPE magnetic attraction material.

[0124] Combined with Examples 3-4 and Examples 7-8 and Comparative Example 5 and Table 3, it can be concluded that by using the preferred ratio of ethylene acrylic acid copolymer and pentaerythritol ester of hydrogenated rosin as tackifiers in the present application, the flexibility and mechanical properties of the prepared flame-retardant TPE magnetic attraction material can be further improved, and it is not easy to crack. In Comparative Example 5, the tackifier is replaced with a compatibilizer, and the properties of the prepared flame-retardant TPE magnetic attraction material all decline. Perhaps because in the absence of the action of the tackifier, the adhesion between the pretreated magnetic powder and TPE is reduced.

[0125] This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A flame retardant TPE magnetic material, characterized in that: It is prepared from the following raw materials in parts by weight: SEBS 5-20 parts Pre-treated magnetic powder 60-80 parts Flame retardant 10-20 parts Plasticizer 5-15 parts Compatibilizer 4-8 parts 2-6 parts of tackifier 1-3 parts lubricant 0.2-1 part of antioxidant; The pretreated magnetic powder is prepared from the following raw materials in parts by weight: Magnetic powder 80-120 parts 4-6 parts of acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer 1-3 parts of tetraethylene glycol diacrylate 3-8 parts of coupling agent 20-50 parts of alcohol solvent; The magnetic powder is neodymium iron boron magnetic powder, and the alcohol solvent is a 60-90wt% ethanol aqueous solution; The coupling agent is composed of bis(dioctyloxypyrophosphate)ethylene titanate and 3-(methacryloyloxy)propyltrimethoxysilane in a weight ratio of 1:(1-3); The pretreated magnetic powder is prepared by the following steps: A1. Add the coupling agent to the alcohol solvent, then add the magnetic powder, raise the temperature to 45-55°C, stir and react to obtain a magnetic powder dispersion; A2. Add acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer and tetraethylene glycol diacrylate to the magnetic powder dispersion, raise the temperature to 65-75°C, stir for 1-2 hours, filter, and dry to obtain pretreated magnetic powder; the tackifier is composed of ethylene acrylic acid copolymer and hydrogenated rosin pentaerythritol ester in a weight ratio of (0.5-1.5):

1.

2. A flame retardant TPE magnetic material according to claim 1, characterized in that: The flame retardant consists of decabromodiphenylethane and antimony trioxide in a weight ratio of 1:(2-4).

3. The flame retardant TPE magnetic material according to claim 1, characterized in that: The compatibilizer is maleic anhydride grafted SEBS and / or maleic anhydride grafted PP.

4. The flame retardant TPE magnetic material according to claim 1, characterized in that: The plasticizer is one or more of white oil, epoxy soybean oil, and tributyl citrate; the lubricant is one or more of polyethylene wax, ethylene bis stearic acid amide, and zinc stearate; and the antioxidant is a hindered phenol antioxidant and / or a phosphite antioxidant.

5. A method for preparing a flame-retardant TPE magnetic material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Add SEBS, flame retardant, plasticizer, compatibilizer, tackifier, lubricant and antioxidant into a mixing device and mix to obtain mixture A; S2. Add the pretreated magnetic powder to the mixture A, mix well, add it to the extrusion equipment for extrusion, cool and granulate to obtain a flame-retardant TPE magnetic material.

6. The method for preparing a flame-retardant TPE magnetic material according to claim 5, characterized in that: The mixing temperature in the step S1 is 150-170°C, and the extrusion temperature in the step S2 is 190-220°C.

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