Low-smoke halogen-free flame-retardant thermoplastic polyester elastomer and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a low-smoke halogen-free flame-retardant thermoplastic polyester elastomer and a preparation method thereof. The low-smoke halogen-free flame-retardant thermoplastic polyester elastomer is prepared from the following raw materials in parts by weight: 60-70 parts of a thermoplastic polyester elastomer, 3-6 parts of a functional aid, 1-5 parts of a synergistic aid, 2-4 parts of an antioxidant and 1-3 parts of calcium stearate, the low-smoke halogen-free flame-retardant thermoplastic polyester elastomer finished product is prepared by mixing the thermoplastic polyester elastomer, the functional additive, the synergistic additive, the antioxidant and the calcium stearate in mixing equipment, melting, and extruding and granulating by an extruder. The low-smoke halogen-free flame-retardant thermoplastic polyester elastomer prepared by the invention not only has better mechanical property, but also has excellent flame-retardant property, and the quality of the low-smoke halogen-free flame-retardant thermoplastic polyester elastomer is effectively ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and specifically to a low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer and a preparation method thereof. Background Art

[0002] As a high-performance elastomer material, thermoplastic polyester elastomer (TPEE) occupies an important position in modern industry by virtue of its excellent comprehensive properties. TPEE belongs to flammable materials, and its limiting oxygen index (LOI) is usually low. It is easy to burn and release a large amount of heat during a fire, which will accelerate the spread of the fire.

[0003] Traditional flame-retardant methods mainly involve adding halogen-based flame retardants, such as bromine-based flame retardants and chlorine-based flame retardants. Although these flame retardants have high flame-retardant effects and can significantly improve the flame-retardant grade of TPEE, they will release a large amount of toxic gases such as hydrogen halide during the combustion process. These gases not only have strong corrosiveness and will cause serious harm to the human respiratory system and eyes, but also cause long-term pollution to the environment.

[0004] Based on this, the present invention provides a low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer and a preparation method thereof to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer and a preparation method thereof. The prepared low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer not only has good mechanical properties, but also has excellent flame-retardant properties, effectively ensuring its quality and quality.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] The first aspect of the present invention: provides a low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer, which is composed of the following raw materials in parts by weight: 60-70 parts of thermoplastic polyester elastomer, 3-6 parts of functional additives, 1-5 parts of synergistic additives, 2-4 parts of antioxidant and 1-3 parts of calcium stearate.

[0008] The present invention is further provided that: the functional additive is composed of bisphenol A bis(diphenyl phosphate) and a flame retardant additive mixed in a mass ratio of 0.08-0.15:1;

[0009] The preparation process of the flame retardant additive is as follows:

[0010] The multi-walled carbon nanotubes are placed in a mixed acid at a dosage ratio of 0.07 - 0.1 g / mL, and refluxed and stirred at 70 - 80 °C for 4 - 6 h. Then, centrifugation is carried out at 8000 - 10000 r / min for 10 - 15 min. The upper clear liquid is removed, washed with deionized water until neutral, and then vacuum dried at 60 - 70 °C for 12 - 14 h to obtain pretreated multi-walled carbon nanotubes;

[0011] The montmorillonite is placed in hydrochloric acid with a mass fraction of 32 - 36% at a dosage ratio of 0.05 - 0.1 g / mL, and stirred at 60 - 70 °C for 4 - 6 h. After filtration, it is washed with deionized water until neutral, dried at 105 - 110 °C for 12 - 14 h, and then ground into powder to obtain pretreated montmorillonite;

[0012] The pretreated multi-walled carbon nanotubes are placed in deionized water at a dosage ratio of 0.02 - 0.08 g / mL and ultrasonically treated for 30 - 40 min. The pretreated montmorillonite and nano-zinc oxide are added thereto, and ultrasonic treatment is continued for 20 - 30 min. Then, stirring is carried out at 300 - 400 r / min for 4 - 5 h, and then heat treatment is carried out at 150 - 160 °C for 10 - 12 h. After cooling to room temperature and centrifugation, the obtained centrifuged product is washed 2 - 4 times each with deionized water and absolute ethanol, and dried at 80 °C for 10 - 12 h and ground into powder to obtain the base material;

[0013] The base material is placed in a silane coupling agent KH550 solution at a dosage ratio of 0.05 - 0.1 g / mL, and stirred at 40 - 60 °C for 2 - 4 h. After centrifugal separation, it is washed 2 - 4 times with absolute ethanol, and then vacuum dried at 60 - 80 °C for 10 - 12 h to obtain the flame retardant aid.

[0014] The present invention is further provided that: the mixed acid is composed of concentrated nitric acid with a mass fraction of 60 - 65% and concentrated sulfuric acid with a mass fraction of 96 - 98% mixed in a volume ratio of 1:3.

[0015] The present invention is further provided that: the added mass of the pretreated montmorillonite is 110 - 120% of the mass of the pretreated multi-walled carbon nanotubes, and the added mass of the nano-zinc oxide is 150 - 200% of the mass of the pretreated multi-walled carbon nanotubes.

[0016] The present invention is further provided that: the silane coupling agent KH550 solution is prepared by dissolving the silane coupling agent KH550 in a mixed solution of absolute ethanol and deionized water to form a solution with a mass fraction of 2 - 5%, wherein the volume ratio of absolute ethanol to deionized water is 9:1.

[0017] The present invention is further provided that: the preparation process of the synergistic aid is as follows:

[0018] Soak the carbon nanofibers in acetone at a dosage ratio of 0.05 - 0.1 g / mL for 20 - 24 h, and then vacuum dry them at 55 - 65 °C until constant weight.

[0019] Put ferrous sulfate into deionized water at a dosage ratio of 0.02 - 0.2 g / mL, treat it at 80 - 120 r / min for 5 - 10 min, add hydrogen peroxide and carbon nanofibers into it, continue to stir at 50 - 70 °C for 180 - 240 min, after suction filtration, wash it with deionized water and ethanol for 2 - 4 times respectively, and then dry it at 60 - 80 °C to obtain the first preform.

[0020] Put hydrotalcite into deionized water at a dosage ratio of 0.05 - 0.15 g / mL and ultrasonically treat it for 20 - 30 min, add 0.2 - 0.3% of cocamidopropyl betaine based on the mass of hydrotalcite into it, treat it at 65 - 75 °C and 120 - 200 r / min for 10 - 12 h, after suction filtration, dry it to obtain the pretreated hydrotalcite; put the pretreated hydrotalcite into deionized water at a dosage ratio of 0.1 - 0.2 / mL and ultrasonically treat it for 20 - 30 min, add 0.08 - 0.12% of melamine cyanurate based on the mass of the pretreated hydrotalcite into it, treat it at 30 - 40 °C and 120 - 200 r / min for 3 - 4 h, after suction filtration, wash it with deionized water for 2 - 4 times, and dry it to obtain the second preform.

[0021] Put zirconium nitrate into N,N - dimethylformamide at a dosage ratio of 0.01 - 0.04 g / mL, and treat it at 80 - 120 r / min for 5 - 10 min to obtain the first solution.

[0022] Put terephthalic acid into N,N - dimethylformamide at a dosage ratio of 0.005 - 0.01 g / mL, and treat it at 80 - 120 r / min for 5 - 10 min to obtain the second solution.

[0023] Treat the first solution and the second solution at a volume ratio of 0.2 - 0.8:1 at 50 - 80 r / min for 5 - 10 min to obtain the third solution.

[0024] Place formic acid in the third solution at a volume ratio of 0.5 - 0.9:1, and treat it for 5 - 10 minutes under the condition of 50 - 80 r / min to obtain the fourth solution. Add the first prefabricated material accounting for 8 - 10% of the mass of the fourth solution and the second prefabricated material accounting for 3 - 5% of the mass of the fourth solution thereto, and treat it for 14 - 16 hours under the condition of 60 - 80 °C. After suction filtration, wash it 2 - 4 times with N,N-dimethylformamide and acetone respectively, and place it under vacuum drying at 50 - 60 °C for 18 - 20 hours to obtain the synergistic auxiliary agent.

[0025] A further setting of the present invention is that: the added mass of hydrogen peroxide is 120 - 150% of the mass of ferrous sulfate, and the added mass of the nanocarbon fiber is 420 - 520% of the mass of ferrous sulfate.

[0026] A further setting of the present invention is that: the antioxidant is selected from any one of antioxidant 619F and antioxidant 168.

[0027] The second aspect of the present invention: It also provides a preparation method of the above-mentioned low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer, including the following steps:

[0028] Step 1: Accurately weigh the thermoplastic polyester elastomer, functional auxiliary agent, synergistic auxiliary agent, antioxidant and calcium stearate, and set aside;

[0029] Step 2: Put the thermoplastic polyester elastomer, functional auxiliary agent, synergistic auxiliary agent, antioxidant and calcium stearate into a mixing device, mix them under the conditions of 30 - 40 °C and 300 - 400 r / min, and extrude and pelletize them through a melting and extruder to prepare the finished product of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer.

[0030] A further setting of the present invention is that: in the said Step 2, the temperatures of the first to sixth zones of the extruder are 195 - 200 °C, 210 - 225 °C, 220 - 235 °C, 220 - 235 °C, 220 - 235 °C and 220 - 235 °C respectively, and the temperature of the die head is 215 - 225 °C.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] In the present invention, thermoplastic polyester elastomer, functional additives, synergistic additives, antioxidant, calcium stearate, etc. are used as raw materials. By putting the thermoplastic polyester elastomer, functional additives, synergistic additives, antioxidant, and calcium stearate into a mixing device for mixing, melting, and then extruding and pelletizing through an extruder, a finished product of low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer is prepared. The low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer prepared by the present invention not only has good mechanical properties but also excellent flame-retardant properties, effectively ensuring its quality and quality. The low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer and its preparation method provided by the present invention have a broader market prospect and are more suitable for popularization. Specific Embodiments

[0033] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0034] Example 1

[0035] This example provides a low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer, which is composed of the following raw materials in parts by weight: 60 parts of thermoplastic polyester elastomer, 3 parts of functional additives, 1 part of synergistic additives, 2 parts of antioxidant, and 1 part of calcium stearate.

[0036] In this example, it should be noted that the thermoplastic polyester elastomer TPEE is purchased from Dongguan Yitai Plastic Chemical Co., Ltd.

[0037] Among them, the functional additives are composed of bisphenol A bis(diphenyl phosphate) and a flame retardant agent mixed in a mass ratio of 0.08:1;

[0038] The preparation process of the flame retardant agent is as follows:

[0039] Put multi-walled carbon nanotubes into a mixed acid at a dosage ratio of 0.07 g / mL, reflux and stir at 70 °C for 4 h, then centrifuge at 8000 r / min for 10 min, remove the upper clear liquid, wash with deionized water until neutral, and then vacuum dry at 60 °C for 12 h to obtain pretreated multi-walled carbon nanotubes;

[0040] Put montmorillonite into hydrochloric acid with a mass fraction of 32% at a dosage ratio of 0.05 g / mL, stir at 60 °C for 4 h, filter, wash with deionized water until neutral, dry at 105 °C for 12 h, and then grind into powder to obtain pretreated montmorillonite;

[0041] The pretreated multi-walled carbon nanotubes were placed in deionized water at a dosage ratio of 0.02 g / mL and ultrasonically treated for 30 min. The pretreated montmorillonite and nano-zinc oxide were added thereto, and the mixture was continuously ultrasonically treated for 20 min. Then, it was stirred at 300 r / min for 4 h, and then heat-treated at 150 °C for 10 h. After cooling to room temperature, the centrifuged product was washed twice with deionized water and absolute ethanol respectively, dried at 80 °C for 10 h, and ground into powder to obtain the base material;

[0042] The base material was placed in a silane coupling agent KH550 solution at a dosage ratio of 0.05 g / mL and stirred at 40 °C for 2 h. After centrifugal separation, it was washed twice with absolute ethanol, and then vacuum dried at 60 °C for 10 h to obtain the flame retardant aid.

[0043] Furthermore, the mixed acid was prepared by mixing concentrated nitric acid with a mass fraction of 60% and concentrated sulfuric acid with a mass fraction of 96% at a volume ratio of 1:3.

[0044] The added mass of the pretreated montmorillonite was 110% of the mass of the pretreated multi-walled carbon nanotubes, and the added mass of the nano-zinc oxide was 150% of the mass of the pretreated multi-walled carbon nanotubes.

[0045] The silane coupling agent KH550 solution was prepared by dissolving the silane coupling agent KH550 in a mixed solution of absolute ethanol and deionized water to form a solution with a mass fraction of 2%, wherein the volume ratio of absolute ethanol to deionized water was 9:1.

[0046] In this embodiment, it should be noted that the multi-walled carbon nanotubes were purchased from Ningbo Luofei Nano Technology Co., Ltd., and the montmorillonite was purchased from Zhejiang Fenghong New Materials Co., Ltd.

[0047] Among them, the preparation process of the synergistic aid is as follows:

[0048] The nano-carbon fibers were soaked in acetone at a dosage ratio of 0.05 g / mL for 20 h, and then vacuum dried at 55 °C to constant weight;

[0049] Ferrous sulfate was placed in deionized water at a dosage ratio of 0.02 g / mL and treated at 80 r / min for 5 min. Hydrogen peroxide and nano-carbon fibers were added thereto, and the mixture was continuously stirred at 50 °C for 180 min. After suction filtration, it was washed twice with deionized water and ethanol respectively, and then dried at 60 °C to obtain the first preform;

[0050] The hydrotalcite was ultrasonically treated in deionized water for 20 min at a dosage ratio of 0.05 g / mL, and 0.2% of cocamidopropyl betaine based on the mass of the hydrotalcite was added thereto. It was treated at 65 °C and 120 r / min for 10 h. After suction filtration and drying, the pretreated hydrotalcite was obtained; the pretreated hydrotalcite was ultrasonically treated in deionized water for 20 min at a dosage ratio of 0.1 / mL, and 0.08% of melamine cyanurate based on the mass of the pretreated hydrotalcite was added thereto. It was treated at 30 °C and 120 r / min for 3 h. After suction filtration, it was washed twice with deionized water and dried to obtain the second preform;

[0051] Zirconium nitrate was placed in N,N-dimethylformamide at a dosage ratio of 0.01 g / mL and treated at 80 r / min for 5 min to obtain the first solution;

[0052] Terephthalic acid was placed in N,N-dimethylformamide at a dosage ratio of 0.005 g / mL and treated at 80 r / min for 5 min to obtain the second solution;

[0053] The first solution and the second solution were treated at 50 r / min for 5 min at a volume ratio of 0.2:1 to obtain the third solution;

[0054] Formic acid was placed in the third solution at a volume ratio of 0.5:1 and treated at 50 r / min for 5 min to obtain the fourth solution. 8% of the first preform and 3% of the second preform based on the mass of the fourth solution were added thereto, and it was treated at 60 °C for 14 h. After suction filtration, it was washed twice with N,N-dimethylformamide and acetone respectively and vacuum dried at 50 °C for 18 h to obtain the synergistic auxiliary agent.

[0055] Furthermore, the added mass of hydrogen peroxide was 120% of the mass of ferrous sulfate, and the added mass of nano-carbon fiber was 420% of the mass of ferrous sulfate.

[0056] In this embodiment, it should be noted that the nano-carbon fiber was purchased from Suzhou Beike Nano Technology Co., Ltd.

[0057] Among them, the antioxidant was selected as antioxidant 619F.

[0058] In addition, this embodiment also provides a preparation method of the above-mentioned low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer, including the following steps:

[0059] Step 1: Accurately weigh the thermoplastic polyester elastomer, functional auxiliary agent, synergistic auxiliary agent, antioxidant and calcium stearate, and set aside;

[0060] Step 2: Put the thermoplastic polyester elastomer, functional additives, synergistic additives, antioxidant and calcium stearate into a mixing device, mix them at 30°C and 300 r / min, melt them, and extrude and pelletize them through an extruder to obtain a finished product of low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer.

[0061] Furthermore, the temperatures of the first to sixth zones of the extruder are 195°C, 210°C, 220°C, 220°C, 220°C and 220°C respectively, and the head temperature is 215°C.

[0062] Example 2

[0063] The preparation method of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer provided in this example is basically the same as that in Example 1, except that: the specific raw material composition and the specific preparation method of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer in this example are different; the specific raw material composition and the specific preparation method of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer in this example are as follows:

[0064] A low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer is composed of the following raw materials in parts by weight: 65 parts of thermoplastic polyester elastomer, 4 parts of functional additives, 2 parts of synergistic additives, 3 parts of antioxidant and 2 parts of calcium stearate.

[0065] In this example, it should be noted that the thermoplastic polyester elastomer TPEE is purchased from Dongguan Yitai Plastic Chemical Co., Ltd.

[0066] Among them, the functional additive is composed of bisphenol A bis(diphenyl phosphate) and a flame retardant additive mixed in a mass ratio of 0.11:1;

[0067] The preparation process of the flame retardant additive is as follows:

[0068] Put multi-walled carbon nanotubes into a mixed acid at a dosage ratio of 0.08 g / mL, reflux and stir at 75°C for 5 h, then centrifuge at 9000 r / min for 102 min, remove the upper clear liquid, wash with deionized water until neutral, and then place in a vacuum at 65°C for 13 h to obtain pretreated multi-walled carbon nanotubes;

[0069] Put montmorillonite into hydrochloric acid with a mass fraction of 34% at a dosage ratio of 0.07 g / mL, stir at 65°C for 5 h, filter, wash with deionized water until neutral, dry at 107°C for 13 h, and then grind into powder to obtain pretreated montmorillonite;

[0070] The pretreated multi-walled carbon nanotubes were placed in deionized water and ultrasonically treated for 35 min at a dosage ratio of 0.04 g / mL. The pretreated montmorillonite and nano-zinc oxide were added thereto, and ultrasonic treatment was continued for 25 min. Then, stirring was carried out at 350 r / min for 5 h, and then heat treatment was carried out at 155 °C for 11 h. After cooling to room temperature, the centrifuged product was washed 3 times each with deionized water and absolute ethanol, dried at 80 °C for 11 h, and ground into powder to obtain the base material;

[0071] The base material was placed in a silane coupling agent KH550 solution at a dosage ratio of 0.07 g / mL and stirred at 50 °C for 3 h. After centrifugal separation, it was washed 3 times with absolute ethanol, and then vacuum dried at 70 °C for 11 h to obtain the flame retardant aid.

[0072] Further, the mixed acid was formed by mixing concentrated nitric acid with a mass fraction of 62% and concentrated sulfuric acid with a mass fraction of 97% at a volume ratio of 1:3.

[0073] The added mass of the pretreated montmorillonite was 115% of the mass of the pretreated multi-walled carbon nanotubes, and the added mass of the nano-zinc oxide was 175% of the mass of the pretreated multi-walled carbon nanotubes.

[0074] The silane coupling agent KH550 solution was prepared by dissolving the silane coupling agent KH550 in a mixed solution of absolute ethanol and deionized water to form a solution with a mass fraction of 3%, wherein the volume ratio of absolute ethanol to deionized water was 9:1.

[0075] In this embodiment, it should be noted that the multi-walled carbon nanotubes were purchased from Ningbo Luofei Nano Technology Co., Ltd., and the montmorillonite was purchased from Zhejiang Fenghong New Materials Co., Ltd.

[0076] Among them, the preparation process of the synergistic aid is as follows:

[0077] The nano-carbon fibers were soaked in acetone at a dosage ratio of 0.07 g / mL for 22 h, and then vacuum dried at 60 °C to constant weight;

[0078] Ferrous sulfate was placed in deionized water at a dosage ratio of 0.1 g / mL and treated at 100 r / min for 7 min. Hydrogen peroxide and nano-carbon fibers were added thereto, and stirring was continued at 60 °C for 210 min. After suction filtration, it was washed 3 times each with deionized water and ethanol, and then dried at 70 °C to obtain the first preform;

[0079] The hydrotalcite was ultrasonically treated in deionized water for 25 min at a dosage ratio of 0.1 g / mL, and 0.2% of cocamidopropyl betaine based on the mass of the hydrotalcite was added thereto. It was treated at 70 °C and 160 r / min for 11 h. After suction filtration and drying, the pretreated hydrotalcite was obtained; the pretreated hydrotalcite was ultrasonically treated in deionized water for 25 min at a dosage ratio of 0.2 / mL, and 0.1% of melamine cyanurate based on the mass of the pretreated hydrotalcite was added thereto. It was treated at 35 °C and 160 r / min for 3 h. After suction filtration, it was washed 3 times with deionized water and dried to obtain the second preform;

[0080] Zirconium nitrate was placed in N,N-dimethylformamide at a dosage ratio of 0.02 g / mL and treated at 100 r / min for 7 min to obtain the first solution;

[0081] Terephthalic acid was placed in N,N-dimethylformamide at a dosage ratio of 0.007 g / mL and treated at 100 r / min for 7 min to obtain the second solution;

[0082] The first solution and the second solution were treated at 65 r / min for 7 min at a volume ratio of 0.4:1 to obtain the third solution;

[0083] Formic acid was placed in the third solution at a volume ratio of 0.7:1 and treated at 65 r / min for 7 min to obtain the fourth solution. 9% of the first preform and 4% of the second preform based on the mass of the fourth solution were added thereto and treated at 70 °C for 15 h. After suction filtration, it was washed 3 times with N,N-dimethylformamide and acetone respectively and vacuum dried at 55 °C for 19 h to obtain the synergistic auxiliary agent.

[0084] Furthermore, the added mass of hydrogen peroxide was 135% of the mass of ferrous sulfate, and the added mass of nanofibrous carbon was 470% of the mass of ferrous sulfate.

[0085] In this example, it should be noted that the nanofibrous carbon was purchased from Suzhou Beike Nano Technology Co., Ltd.

[0086] Among them, the antioxidant was selected as antioxidant 168.

[0087] In addition, this example also provides a preparation method of the above-mentioned low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer, including the following steps:

[0088] Step 1: Accurately weigh the thermoplastic polyester elastomer, functional auxiliary agent, synergistic auxiliary agent, antioxidant and calcium stearate for standby;

[0089] Step 2: Put the thermoplastic polyester elastomer, functional additives, synergistic additives, antioxidant and calcium stearate into a mixing device, mix them under the conditions of 35°C and 350 r / min, melt them, and extrude and pelletize them through an extruder to obtain a finished product of low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer.

[0090] Further, the temperatures of the first to sixth zones of the extruder are 200°C, 225°C, 235°C, 235°C, 235°C and 235°C respectively, and the head temperature is 225°C.

[0091] Example 3

[0092] The preparation method of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer provided in this example is basically the same as that in Example 1, except that: the specific raw material composition and the specific preparation method of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer in this example are different; the specific raw material composition and the specific preparation method of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer in this example are as follows:

[0093] A low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer is composed of the following raw materials in parts by weight: 70 parts of thermoplastic polyester elastomer, 6 parts of functional additives, 5 parts of synergistic additives, 4 parts of antioxidant and 3 parts of calcium stearate.

[0094] In this example, it should be noted that the thermoplastic polyester elastomer TPEE is purchased from Dongguan Yitai Plastic Chemical Co., Ltd.

[0095] Among them, the functional additives are composed of bisphenol A bis(diphenyl phosphate) and a flame retardant mixed in a mass ratio of 0.15:1;

[0096] The preparation process of the flame retardant is as follows:

[0097] Put multi-walled carbon nanotubes into a mixed acid at a dosage ratio of 0.1 g / mL, reflux and stir at 80°C for 6 h, then centrifuge at 10000 r / min for 15 min, remove the upper clear liquid, wash with deionized water until neutral, and then place it under vacuum drying at 70°C for 14 h to obtain pretreated multi-walled carbon nanotubes;

[0098] Put montmorillonite into hydrochloric acid with a mass fraction of 36% at a dosage ratio of 0.1 g / mL, stir at 70°C for 6 h, filter, wash with deionized water until neutral, dry at 110°C for 14 h, and then grind into powder to obtain pretreated montmorillonite;

[0099] The pretreated multi-walled carbon nanotubes were placed in deionized water at a dosage ratio of 0.08 g / mL and ultrasonically treated for 40 min. The pretreated montmorillonite and nano-zinc oxide were added thereto, and ultrasonic treatment was continued for 30 min. Then, stirring was carried out for 5 h under the condition of 400 r / min, and then heat treatment was carried out at 160 °C for 12 h. After cooling to room temperature, the obtained centrifuged product was washed 4 times each with deionized water and absolute ethanol, dried at 80 °C for 12 h, and ground into powder to obtain a base material;

[0100] The base material was placed in a silane coupling agent KH550 solution at a dosage ratio of 0.1 g / mL, stirred at 60 °C for 4 h, and after centrifugal separation, washed 4 times with absolute ethanol, and then vacuum dried at 80 °C for 12 h to obtain a flame retardant aid.

[0101] Furthermore, the mixed acid was prepared by mixing concentrated nitric acid with a mass fraction of 65% and concentrated sulfuric acid with a mass fraction of 98% at a volume ratio of 1:3.

[0102] The added mass of the pretreated montmorillonite was 120% of the mass of the pretreated multi-walled carbon nanotubes, and the added mass of the nano-zinc oxide was 200% of the mass of the pretreated multi-walled carbon nanotubes.

[0103] The silane coupling agent KH550 solution was prepared by dissolving the silane coupling agent KH550 in a mixed solution of absolute ethanol and deionized water to form a solution with a mass fraction of 5%, wherein the volume ratio of absolute ethanol to deionized water was 9:1.

[0104] In this embodiment, it should be noted that the multi-walled carbon nanotubes were purchased from Ningbo Luofei Nano Technology Co., Ltd., and the montmorillonite was purchased from Zhejiang Fenghong New Materials Co., Ltd.

[0105] Among them, the preparation process of the synergistic aid is as follows:

[0106] The nano-carbon fibers were soaked in acetone at a dosage ratio of 0.1 g / mL for 24 h, and then vacuum dried to constant weight at 55-65 °C;

[0107] Ferrous sulfate was placed in deionized water at a dosage ratio of 0.2 g / mL, treated at 120 r / min for 10 min, hydrogen peroxide and nano-carbon fibers were added thereto, and stirring was continued at 70 °C for 240 min. After suction filtration, it was washed 4 times each with deionized water and ethanol, and then dried at 80 °C to obtain a first preform;

[0108] The hydrotalcite was placed in deionized water and ultrasonically treated for 30 min at a dosage ratio of 0.15 g / mL. Then, cocamidopropyl betaine accounting for 0.3% of the mass of the hydrotalcite was added thereto, and the mixture was treated at 75 °C and 200 r / min for 12 h. After suction filtration and drying, the pretreated hydrotalcite was obtained; the pretreated hydrotalcite was ultrasonically treated in deionized water for 30 min at a dosage ratio of 0.2 / mL, and melamine cyanurate accounting for 0.12% of the mass of the pretreated hydrotalcite was added thereto. The mixture was treated at 40 °C and 200 r / min for 4 h. After suction filtration, it was washed 4 times with deionized water and then dried to obtain the second preform;

[0109] Zirconium nitrate was placed in N,N-dimethylformamide at a dosage ratio of 0.04 g / mL and treated at 120 r / min for 10 min to obtain the first solution;

[0110] Terephthalic acid was placed in N,N-dimethylformamide at a dosage ratio of 0.01 g / mL and treated at 120 r / min for 10 min to obtain the second solution;

[0111] The first solution and the second solution were treated at 80 r / min for 10 min at a volume ratio of 0.8:1 to obtain the third solution;

[0112] Formic acid was added to the third solution at a volume ratio of 0.9:1 and treated at 80 r / min for 10 min to obtain the fourth solution. Then, the first preform accounting for 10% of the mass of the fourth solution and the second preform accounting for 5% of the mass of the fourth solution were added thereto. The mixture was treated at 80 °C for 16 h. After suction filtration, it was washed 4 times with N,N-dimethylformamide and acetone respectively, and then vacuum dried at 60 °C for 20 h to obtain the synergistic auxiliary agent.

[0113] Furthermore, the added mass of hydrogen peroxide was 150% of the mass of ferrous sulfate, and the added mass of nano-carbon fiber was 520% of the mass of ferrous sulfate.

[0114] In this example, it should be noted that the nano-carbon fiber was purchased from Suzhou Beike Nano Technology Co., Ltd.

[0115] Among them, the antioxidant was selected as antioxidant 619F.

[0116] In addition, this example also provides a preparation method of the above-mentioned low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer, including the following steps:

[0117] Step 1: Accurately weigh the thermoplastic polyester elastomer, functional auxiliary agent, synergistic auxiliary agent, antioxidant and calcium stearate, and set aside;

[0118] Step 2: Put the thermoplastic polyester elastomer, functional additives, synergistic additives, antioxidant and calcium stearate into a mixing device, mix them under the conditions of 40°C and 400 r / min, melt them, and extrude and pelletize them through an extruder to obtain a finished product of low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer.

[0119] Further, the temperatures of the first to sixth zones of the extruder are 200°C, 225°C, 235°C, 235°C, 235°C and 235°C respectively, and the head temperature is 225°C.

[0120] Comparative Example 1: The difference from Example 1 is that this example does not contain functional additives.

[0121] Comparative Example 2: The difference from Example 1 is that this example does not contain synergistic additives.

[0122] Performance test: Mark the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer samples provided in Examples 1 to 3 and Comparative Examples 1 to 2 as Examples 1 to 3 and Comparative Examples 1 to 2 respectively; and conduct the following tests on the relevant properties of the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomers provided in Examples 1 to 3 and Comparative Examples 1 to 2:

[0123] 1. Flame retardancy test: The test method is to test according to the "UL94 Plastic Combustion Performance Test Standard" and use an oxygen index meter to test its LOI value (the test standard selects the national standard GB / T 2406 of China).

[0124] 2. Tensile strength and elongation at break test: The test method is to test according to ISO 527-1, 2 standards.

[0125] The obtained test data are recorded in Table 1 and Table 2 below:

[0126] Table 1 Flame Retardancy Test Results of Each Group of Thermoplastic Polyester Elastomers

[0127] Group Flame retardancy rating (1.5 mm) LOI (%) Example 1 group V-0 35 Example 2 group V-0 33 Example 3 group V-0 35 Control 1 group NR 27 Control 2 group NR 25

[0128] Table 2 Mechanical Property Test Results of Each Group of Thermoplastic Polyester Elastomers

[0129] Group Tensile strength (MPa) Elongation at break (%) Example 1 group 39 520 Example 2 group 38 412 Example 3 group 38 408 Control 1 group 28 331 Control 2 group 25 255

[0130] By comparing and analyzing the relevant data in Table 1 and Table 2, it can be seen that the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer prepared by the present invention not only has good mechanical properties, but also has excellent flame retardancy, effectively ensuring its quality and quality. This shows that the low-smoke and halogen-free flame-retardant thermoplastic polyester elastomer and its preparation method provided by the present invention have a broader market prospect and are more suitable for promotion.

[0131] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0132] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer, characterized in that: The invention is composed of the following raw materials in parts by weight: 60-70 parts of thermoplastic polyester elastomer, 3-6 parts of functional additives, 1-5 parts of synergistic additives, 2-4 parts of antioxidants and 1-3 parts of calcium stearate.

2. The low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to claim 1, characterized in that: The functional additive is prepared by mixing bisphenol A bis(diphenyl phosphate) and a flame retardant additive in a mass ratio of 0.08 to 0.15:1; The preparation process of the flame retardant additive is as follows: The multi-walled carbon nanotubes are placed in a mixed acid at a dosage ratio of 0.07 to 0.1 g / mL, refluxed and stirred at 70 to 80° C. for 4 to 6 hours, then centrifuged at 8000 to 10000 r / min for 10 to 15 minutes, the supernatant is removed, washed with deionized water until neutral, and then placed at 60 to 70° C. for vacuum drying for 12 to 14 hours to obtain pretreated multi-walled carbon nanotubes; The montmorillonite is placed in hydrochloric acid with a mass fraction of 32-36% at a dosage ratio of 0.05-0.1 g / mL, stirred at 60-70° C. for 4-6 hours, filtered, washed with deionized water until neutral, dried at 105-110° C. for 12-14 hours, and then ground into powder to obtain pretreated montmorillonite; The pretreated multi-walled carbon nanotubes were placed in deionized water for ultrasonic treatment for 30 to 40 minutes at a dosage ratio of 0.02 to 0.08 g / mL, the pretreated montmorillonite and nano zinc oxide were added thereto, the ultrasonic treatment was continued for 20 to 30 minutes, and then stirred at 300 to 400 r / min for 4 to 5 hours, and then heat treated at 150 to 160° C. for 10 to 12 hours, cooled to room temperature, and centrifuged. The obtained centrifugal product was washed with deionized water and anhydrous ethanol for 2 to 4 times respectively, dried at 80° C. for 10 to 12 hours, and ground into powder to obtain a base material; The base material is placed in a silane coupling agent KH550 solution at a dosage ratio of 0.05-0.1 g / mL, stirred at 40-60° C. for 2-4 hours, centrifuged, washed with anhydrous ethanol for 2-4 times, and then vacuum dried at 60-80° C. for 10-12 hours to obtain a flame retardant additive.

3. The low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to claim 2, characterized in that: The mixed acid is prepared by mixing concentrated nitric acid with a mass fraction of 60-65% and concentrated sulfuric acid with a mass fraction of 96-98% in a volume ratio of 1:

3.

4. The low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to claim 2, characterized in that: The added mass of the pretreated montmorillonite is 110-120% of the mass of the pretreated multi-walled carbon nanotubes, and the added mass of the nano zinc oxide is 150-200% of the mass of the pretreated multi-walled carbon nanotubes.

5. The low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to claim 2, characterized in that: The silane coupling agent KH550 solution is prepared by dissolving the silane coupling agent KH550 in a mixed solution of anhydrous ethanol and deionized water to prepare a solution with a mass fraction of 2-5%, wherein the volume ratio of anhydrous ethanol to deionized water is 9:

1.

6. The low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to claim 1, characterized in that: The preparation process of the synergistic aid is as follows: Soak the carbon nanofibers in acetone at a dosage of 0.05 to 0.1 g / mL for 20 to 24 hours, and then dry them in a vacuum at 55 to 65°C until constant weight; The ferrous sulfate is placed in deionized water at a dosage ratio of 0.02 to 0.2 g / mL, and treated at 80 to 120 r / min for 5 to 10 minutes, hydrogen peroxide and nano-carbon fibers are added thereto, and stirring is continued at 50 to 70° C. for 180 to 240 minutes. After suction filtration, the mixture is washed with deionized water and ethanol for 2 to 4 times, and then dried at 60 to 80° C. to obtain a first prefabricated material; The hydrotalcite is ultrasonically treated in deionized water at a dosage ratio of 0.05 to 0.15 g / mL for 20 to 30 minutes, 0.2 to 0.3% of the mass of the hydrotalcite is added thereto, and the mixture is treated at 65 to 75° C. and 120 to 200 r / min for 10 to 12 hours, and then filtered and dried to obtain a pretreated hydrotalcite; the pretreated hydrotalcite is ultrasonically treated in deionized water at a dosage ratio of 0.1 to 0.2 / mL for 20 to 30 minutes, 0.08 to 0.12% of the mass of the pretreated hydrotalcite is added thereto, and the mixture is treated at 30 to 40° C. and 120 to 200 r / min for 3 to 4 hours, filtered, washed with deionized water for 2 to 4 times, and dried to obtain a second prefabricated material; Place zirconium nitrate in N,N-dimethylformamide at a dosage ratio of 0.01 to 0.04 g / mL, and treat at 80 to 120 r / min for 5 to 10 minutes to obtain a first solution; Put terephthalic acid in N,N-dimethylformamide at a dosage ratio of 0.005-0.01 g / mL, and treat at 80-120 r / min for 5-10 min to obtain a second solution; The first solution and the second solution are treated at a volume ratio of 0.2 to 0.8:1 at 50 to 80 r / min for 5 to 10 minutes to obtain a third solution; Formic acid is placed in the third solution at a volume ratio of 0.5 to 0.9:1, and treated at 50 to 80 r / min for 5 to 10 minutes to obtain a fourth solution, to which 8 to 10% of the mass of the fourth solution and 3 to 5% of the mass of the second prefabricated material are added, and the solution is treated at 60 to 80° C. for 14 to 16 hours. After filtration, the solution is washed with N,N-dimethylformamide and acetone for 2 to 4 times, and the solution is dried under vacuum at 50 to 60° C. for 18 to 20 hours to obtain a synergistic additive.

7. The low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to claim 6, characterized in that: The added mass of the hydrogen peroxide is 120-150% of the mass of the ferrous sulfate, and the added mass of the nano-carbon fiber is 420-520% of the mass of the ferrous sulfate.

8. The low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to claim 1, characterized in that: The antioxidant is selected from any one of antioxidant 619F and antioxidant 168.

9. The method for preparing a low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1: accurately weigh thermoplastic polyester elastomer, functional additive, synergistic additive, antioxidant and calcium stearate for later use; Step 2: Put the thermoplastic polyester elastomer, functional additives, synergistic additives, antioxidants and calcium stearate into a mixing device, mix them at 30-40° C. and 300-400 r / min, melt them, extrude them into granules through an extruder, and prepare a low-smoke, halogen-free, flame-retardant thermoplastic polyester elastomer finished product.

10. The method for preparing a low-smoke halogen-free flame-retardant thermoplastic polyester elastomer according to claim 9, characterized in that: In the step 2, the temperatures of zones 1 to 6 of the extruder are 195-200°C, 210-225°C, 220-235°C, 220-235°C, 220-235°C and 220-235°C, respectively, and the die head temperature is 215-225°C.