Environment-friendly flame-retardant pipe and preparation method thereof

Abstract

The invention relates to the field of flame-retardant materials, in particular to an environment-friendly flame-retardant pipe and a preparation method thereof.The environment-friendly flame-retardant pipe is prepared from, by weight, 75-95 parts of polypropylene, 13-26 parts of maleic anhydride grafted polypropylene, 10-20 parts of activated calcium carbonate, 15-25 parts of environment-friendly flame retardant, 2-4 parts of lubricant, 1.5-3 parts of antioxidant, 0.8-1.6 parts of light stabilizer and 1.2-2.4 parts of heat stabilizer; the environment-friendly flame retardant is prepared by carrying out binding reaction on vinyl sulfonamide sulfadiazine and thiolated zirconium phosphate. The flame-retardant pipe prepared by the invention not only has environmental protection property and excellent flame retardance, but also has higher strength and better impact resistance compared with a traditional polypropylene flame-retardant pipe, so that the flame-retardant pipe is more durable and longer in service life, and the replacement frequency and related maintenance cost are reduced.

Description

Technical Field

[0001] The invention relates to the field of flame retardant materials, and in particular to an environmentally friendly flame retardant pipe and a preparation method thereof. Background Art

[0002] Flame retardant pipes are suitable for conveying liquids with general working pressure in the fields of industry, agriculture, food, medicine, civil engineering, fishery, aquaculture, garden irrigation, etc. Such as: pneumatic pipes, hydraulic pipes, garden hoses, oil and water pipelines, oil exploration pipes, sandblasting pipes, peristaltic pump hoses, industrial robots, pneumatic tools, assembly plant air pressure tools, pressure conveying pipelines, can be used as vacuum straws, protective jackets or decorations for metal and electronic products. Among them, polypropylene flame retardant pipes are the most commonly used varieties. Polypropylene (PP) is a lightweight, corrosion-resistant, aging-resistant, and easy-to-install material. It is widely used in many fields due to its excellent mechanical properties, easy processing and low cost. However, since polypropylene is easy to burn when exposed to open flames, high temperatures or oxygen, it will emit black smoke and toxic gases when burning, which will have adverse effects on the human body and the environment. Therefore, flame retardants are usually added to improve its flame retardant properties.

[0003] At present, there are many studies and reports on polypropylene materials with high flame retardancy on the market, and the flame retardants involved mainly include halogen, phosphorus, nitrogen, nitrogen-phosphorus composite and inorganic flame retardants. However, halogen flame retardants are not environmentally friendly, and other types of flame retardants also have the defects of poor flame retardant effect or poor compatibility with polypropylene, which leads to the inability to achieve satisfactory results in the application of polypropylene. Therefore, it is extremely important to find a flame retardant material that can maintain the high performance of polypropylene while ensuring flame retardancy. Summary of the invention

[0004] In view of the problems existing in the prior art, the object of the present invention is to provide an environmentally friendly flame retardant tube and a preparation method thereof.

[0005] The purpose of the present invention is achieved by the following technical solutions: In a first aspect, the present invention provides an environmentally friendly flame-retardant tube, calculated by weight, comprising: 75-95 parts of polypropylene, 13-26 parts of maleic anhydride grafted polypropylene, 10-20 parts of activated calcium carbonate, 15-25 parts of environmentally friendly flame retardant, 2-4 parts of lubricant, 1.5-3 parts of antioxidant, 0.8-1.6 parts of light stabilizer and 1.2-2.4 parts of heat stabilizer.

[0006] Preferably, the density of the polypropylene is 0.943-0.958 g / cm 3 , the melt index is 1.2-3.6g / 10min (190℃, 2.16kg).

[0007] Preferably, the grafting rate of the maleic anhydride grafted polypropylene PP-g-MAH is 0.8-1.2%, and the density is 0.912-0.926 g / cm 3 , the melt index is 50-80g / 10min (190℃, 2.16kg).

[0008] Preferably, the activated calcium carbonate is calcium carbonate activated by a silane coupling agent; wherein the silane coupling agent is one of KH550, KH560 and KH570.

[0009] Preferably, the preparation process of the activated calcium carbonate comprises: Mix 5-8 μm calcium carbonate powder and silane coupling agent in 30%-50% ethanol solution by mass, reflux at 75-85°C for 3-10 hours, and after the treatment, separate the solid by centrifugation, wash it three times with water, and then vacuum dry it to obtain activated calcium carbonate; The mass volume ratio of calcium carbonate powder, silane coupling agent and ethanol solution is 1g:(0.1-0.5)g:(10-20)mL.

[0010] Preferably, the environmentally friendly flame retardant is prepared by reacting vinylsulfonamidated sulfadiazine and thiolated zirconium phosphate.

[0011] Preferably, the lubricant is a mixture of one or more of zinc stearate, calcium stearate, liquid paraffin, oxidized polyethylene wax, and ethylene bisstearamide.

[0012] Preferably, the antioxidant is a mixture of one or more of antioxidant 168, antioxidant 626, antioxidant 1076, and antioxidant 1010.

[0013] Preferably, the light stabilizer is a hindered amine light stabilizer, including a mixture of one or more of light stabilizer 622, light stabilizer 770, light stabilizer 783, and light stabilizer 944.

[0014] Preferably, the heat stabilizer is an organic tin heat stabilizer, including a mixture of one or more of dioctyltin dilaurate, dibutyltin maleate, dibutyltin bis(monobutyl maleate), dioctyltin maleate, and dibutyltin bis(monooctyl maleate).

[0015] Preferably, the preparation method of the environmentally friendly flame retardant comprises: S1. Weigh zirconium phosphate powder and ethanol solution, mix them, fully disperse them in an ultrasonic disperser, add a mercaptosilane coupling agent, stir them in a water bath at 60-80° C. for 5-10 hours, separate, wash and dry them after the reaction is completed to obtain mercapto zirconium phosphate ZP-SH; S2, weigh sulfadiazine, triethylamine and sodium hydroxide solution, mix them in a beaker, stir and disperse them evenly at room temperature to obtain a sulfadiazine mixed solution; weigh 4-vinylbenzenesulfonyl chloride and acetone, mix them in a flask, add the sulfadiazine mixed solution drop by drop, and after the addition is completed, heat it to 70-90° C., reflux and stir to react for 10-20 hours, and after the reaction is completed, remove the solvent, wash and dry to obtain vinyl sulfonamidated sulfadiazine; S3. Weigh thiolated zirconium phosphate and vinylsulfonamidated sulfadiazine separately, add them into dimethyl sulfoxide, stir and disperse them evenly at room temperature, add photoinitiator, stir and react for 0.5-1.5h under LED ultraviolet lamp, and after the reaction, remove the solvent under reduced pressure to obtain an environmentally friendly flame retardant.

[0016] Preferably, in S1, the particle size of the zirconium phosphate powder (Zn3B2O6, ZP) is 12-18 μm, and the manufacturer is Shandong Yueyang New Materials Co., Ltd.

[0017] Preferably, in S1, the mass volume ratio of zirconium phosphate powder, mercaptosilane coupling agent and anhydrous ethanol is 10g:(1.3-2.6)g:(50-100)mL.

[0018] Preferably, in S1, the mercaptosilane coupling agent is one or more of γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropylmethyldimethoxysilane.

[0019] Preferably, in the sulfadiazine mixed solution of S2, the concentration of the sodium hydroxide solution is 0.1-0.6 mol / L, and the mass volume ratio of sulfadiazine, triethylamine and sodium hydroxide solution is (2.5-7.5) g: (1-2) g: (30-50) mL.

[0020] Preferably, in S2, the mass volume ratio of the mixed solution of 4-vinylbenzenesulfonyl chloride, acetone and sulfadiazine is (2.1-6.3) g: (15-25) mL: (35-55) mL.

[0021] Preferably, in S2, the stirring speed is 250-450 r / min, and the dropping speed is 3-10 mL / min.

[0022] Preferably, in S3, the mass volume ratio of thiolated zirconium phosphate, vinylsulfonamidated sulfadiazine and dimethyl sulfoxide is 1 g: (0.34-0.68) g: (15-25) mL.

[0023] Preferably, in S3, the photoinitiator is benzoin dimethyl ether, and the amount added is 2%-8% of the mass of vinylsulfonamidated sulfadiazine.

[0024] Preferably, in S3, the wavelength of the LED ultraviolet lamp is 325-390nm, and the light intensity is 1.5-2.5mW / cm 2 .

[0025] In a second aspect, the present invention provides a method for preparing an environmentally friendly flame-retardant tube, comprising the following steps: Step 1, weighing each raw material according to the weight, then mixing each raw material in a blender, and fully blending at a speed of 500-800 r / min to obtain a mixed raw material; Step 2, introducing the mixed raw materials into a twin-screw extruder, extruding and granulating at a temperature of 175-205° C. to obtain a flame retardant material masterbatch; Step 3, placing the flame retardant material masterbatch in a mold for processing and molding, and finally obtaining an environmentally friendly flame retardant tube.

[0026] The beneficial effects of the present invention are: 1. The present invention prepares an environmentally friendly flame-retardant tube, which is obtained by processing and molding a flame-retardant material masterbatch. The flame-retardant tube prepared by the present invention is not only environmentally friendly and has excellent flame retardancy, but also has higher strength and better impact resistance than traditional polypropylene flame-retardant tubes, so that the flame-retardant tube is more durable and has a longer service life, reducing the replacement frequency and related maintenance costs.

[0027] 2. The flame retardant masterbatch prepared by the present invention adopts light-weight, heat-resistant and chemically stable polypropylene as the main material; activated calcium carbonate is used as the main filler to improve the rigidity, heat resistance and dimensional stability of polypropylene while reducing the cost; the addition of maleic anhydride grafted polypropylene enhances the adhesion and compatibility of polypropylene with polar materials; the addition of environmentally friendly flame retardants not only improves the flame retardant properties of polypropylene, but also enhances the various performances of polypropylene; in addition, a variety of additives are added to assist in enhancing the performance of polypropylene.

[0028] 3. The environmentally friendly flame retardant used in the present invention is prepared by using thiolated zirconium phosphate as a matrix and reacting with vinyl sulfonamidated sulfadiazine through a thiol-double bond click reaction. Vinyl sulfonamidated sulfadiazine is obtained by using sulfadiazine and 4-vinylbenzenesulfonyl chloride through an acyl chloride-amino group combination reaction, wherein sulfadiazine provides an amino group and combines with the sulfonyl chloride in 4-vinylbenzenesulfonyl chloride to generate a sulfonamide group, thereby obtaining vinyl sulfonamidated sulfadiazine.

[0029] 4. In the process of preparing the environmentally friendly flame retardant of the present invention, since the structure of vinyl sulfonamidated sulfadiazine contains more sulfonamide groups than that of sulfadiazine, and the vinyl groups therein combine with the thiolated zirconium phosphate to form thioether groups, the prepared flame retardant has better flame retardancy. And after testing, it was found that the flame retardant also has a certain degree of improvement in the physical properties of polypropylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0031] Figure 1 Schematic diagram of scanning electron microscope of the environmentally friendly flame retardant prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is described below through specific examples. It should be understood that the one or more method steps mentioned in the present invention do not exclude the existence of other method steps before and after the combination step or the insertion of other method steps between these explicitly mentioned steps; it should also be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. The change or adjustment of the relative relationship thereof shall also be regarded as the scope of the present invention without substantially changing the technical content.

[0033] In order to better understand the above technical scheme, the exemplary embodiments of the present invention are described in more detail below. Although exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0034] The present invention will be further described below in conjunction with the following examples. Example 1

[0035] An environmentally friendly flame retardant tube, calculated by weight, comprising: 85 parts of polypropylene, 18 parts of maleic anhydride grafted polypropylene, 15 parts of activated calcium carbonate, 20 parts of environmentally friendly flame retardant, 3 parts of lubricant, 2.1 parts of antioxidant, 1.2 parts of light stabilizer and 1.8 parts of heat stabilizer.

[0036] Among them, the density of polypropylene is 0.947g / cm 3 , the melt index is 2.4g / 10min (190℃, 2.16kg); the grafting rate of maleic anhydride grafted polypropylene PP-g-MAH is 1%, and the density is 0.918g / cm 3, the melt index is 65g / 10min (190℃, 2.16kg); the lubricant is zinc stearate; the antioxidant is antioxidant 168; the light stabilizer is light stabilizer 622; and the heat stabilizer is di-n-octyltin dilaurate.

[0037] The preparation process of activated calcium carbonate includes: 1 g of 5-8 μm calcium carbonate powder and 0.3 g of KH550 were mixed in 15 mL of 40 wt% ethanol solution and refluxed at 80 °C for 6 h. After the treatment, the solid was separated by centrifugation, washed three times with water and then vacuum dried to obtain activated calcium carbonate.

[0038] Wherein, the preparation method of the environmentally friendly flame retardant comprises: S1. Weigh zirconium phosphate powder (ZP) and 50wt% ethanol solution, mix them, fully disperse them in an ultrasonic disperser, add γ-mercaptopropyltrimethoxysilane, the mass volume ratio of zirconium phosphate powder, γ-mercaptopropyltrimethoxysilane and anhydrous ethanol is 10g:2.1g:80mL, stir in a 70°C water bath for 8h, after the reaction is completed, separate the solid and wash it with alcohol for at least three times, and dry it under vacuum to obtain thiolated zirconium phosphate (ZP-SH); S2. Weigh sulfadiazine (SD), triethylamine (TEA) and 0.5 mol / L sodium hydroxide solution and mix them in a beaker. The mass volume ratio of sulfadiazine, triethylamine and sodium hydroxide solution is 5g:1.5g:40mL. Stir and disperse them evenly at room temperature to obtain a sulfadiazine mixed solution. Weigh 4-vinylbenzenesulfonyl chloride (p-VSCl) and acetone and mix them in a flask. Pass nitrogen as a protective gas. At room temperature, add the sulfadiazine mixed solution drop by drop at a rate of 8mL / mi n, adding dropwise while stirring, the stirring speed is 350r / min, the mass volume ratio of the mixed solution of 4-vinylbenzenesulfonyl chloride, acetone and sulfadiazine is 4.2g:20mL:45mL, after the addition is completed, the temperature is raised to 80°C, refluxed and stirred for 15h, after the reaction is completed, the solvent is first removed by rotary evaporation, and then the product is washed with 5% saline solution until the washing liquid is neutral, and then washed with pure water three times, and dried under vacuum to obtain vinyl sulfonamidated sulfadiazine (VSN-SD); S3. Weigh zirconium thiophosphate (ZP-SH) and vinyl sulfonamidated sulfadiazine (VSN-SD) respectively and add them into dimethyl sulfoxide (DMSO). The mass volume ratio of zirconium thiophosphate, vinyl sulfonamidated sulfadiazine and DMSO is 1g:0.51g:20mL. Stir and disperse them evenly at room temperature. Add 5% of the mass of vinyl sulfonamidated sulfadiazine dimethyl ether (DMPA) as a photoinitiator at a wavelength of 365nm and a light intensity of 2mW / cm 2The reaction was stirred for 1 hour under the irradiation of LED ultraviolet light. After the reaction was completed, the solvent was removed under reduced pressure to obtain an environmentally friendly flame retardant.

[0039] The method for preparing the above-mentioned environmentally friendly flame-retardant tube comprises the following steps: Step 1, weighing and calculating each raw material according to the weight, then mixing each raw material in a blender, and fully blending at a speed of 650 r / min to obtain a mixed raw material; Step 2, introducing the mixed raw materials into a twin-screw extruder, extruding and granulating at a temperature of 175-205° C. to obtain a flame retardant material masterbatch; Step 3, placing the flame retardant material masterbatch in a mold for processing and molding, and finally obtaining an environmentally friendly flame retardant tube. Example 2

[0040] An environmentally friendly flame retardant tube, calculated by weight, comprising: 75 parts of polypropylene, 13 parts of maleic anhydride grafted polypropylene, 10 parts of activated calcium carbonate, 15 parts of environmentally friendly flame retardant, 2 parts of lubricant, 1.5 parts of antioxidant, 0.8 parts of light stabilizer and 1.2 parts of heat stabilizer.

[0041] The density of polypropylene is 0.947 g / cm 3 , the melt index is 2.4g / 10min (190℃, 2.16kg); the grafting rate of maleic anhydride grafted polypropylene PP-g-MAH is 1%, and the density is 0.918g / cm 3 , the melt index is 65g / 10min (190℃, 2.16kg); the lubricant is liquid paraffin; the antioxidant is antioxidant 626; the light stabilizer is light stabilizer 770; and the heat stabilizer is dibutyltin maleate.

[0042] The preparation process of activated calcium carbonate includes: 5-8μm calcium carbonate powder and KH560 were mixed in an ethanol solution with a mass fraction of 30%-50%. The mass volume ratio of calcium carbonate powder, KH560 and ethanol solution was 1g:0.1g:10mL. The mixture was refluxed at 75°C for 3h. After the treatment, the solid was separated by centrifugation, washed three times with water and then vacuum dried to obtain activated calcium carbonate.

[0043] Wherein, the preparation method of the environmentally friendly flame retardant comprises: S1. Weigh zirconium phosphate powder (ZP) and 50wt% ethanol solution, mix them, fully disperse them in an ultrasonic disperser, add γ-mercaptopropyltriethoxysilane, the mass volume ratio of zirconium phosphate powder, γ-mercaptopropyltriethoxysilane and anhydrous ethanol is 10g:1.3g:50mL, stir in a 70°C water bath for 8h, after the reaction is completed, separate the solid and wash it with alcohol for at least three times, and dry it under vacuum to obtain thiolated zirconium phosphate (ZP-SH); S2. Weigh sulfadiazine (SD), triethylamine (TEA) and 0.1 mol / L sodium hydroxide solution and mix them in a beaker. The mass volume ratio of sulfadiazine, triethylamine and sodium hydroxide solution is 2.5 g:1 g:30 mL. Stir and disperse them evenly at room temperature to obtain a sulfadiazine mixed solution. Weigh 4-vinylbenzenesulfonyl chloride (p-VSCl) and acetone and mix them in a flask. Pass nitrogen as a protective gas. At room temperature, add the sulfadiazine mixed solution drop by drop at a rate of 3 mL / min. n, adding dropwise while stirring, the stirring speed is 250r / min, the mass volume ratio of the mixed solution of 4-vinylbenzenesulfonyl chloride, acetone and sulfadiazine is 2.1g:15mL:35mL, after the addition is completed, the temperature is raised to 70°C, refluxed and stirred for 10h, after the reaction is completed, the solvent is first removed by rotary evaporation, and then the product is washed with 5% saline solution until the washing liquid is neutral, and then washed with pure water three times, and dried under vacuum to obtain vinyl sulfonamidated sulfadiazine (VSN-SD); S3. Weigh zirconium thiophosphate (ZP-SH) and vinyl sulfonamidated sulfadiazine (VSN-SD) respectively and add them into dimethyl sulfoxide (DMSO). The mass volume ratio of zirconium thiophosphate, vinyl sulfonamidated sulfadiazine and DMSO is 1g:0.34g:15mL. Stir and disperse them evenly at room temperature. Add 2% of the mass of vinyl sulfonamidated sulfadiazine dimethyl ether (DMPA) as a photoinitiator at a wavelength of 365nm and a light intensity of 1.5mW / cm 2 The reaction was stirred for 0.5 h under the irradiation of LED ultraviolet light. After the reaction was completed, the solvent was removed under reduced pressure to obtain an environmentally friendly flame retardant.

[0044] The method for preparing the above-mentioned environmentally friendly flame-retardant tube comprises the following steps: Step 1, weighing each raw material according to the weight, then mixing each raw material in a blender, and fully blending at a speed of 500 r / min to obtain a mixed raw material; Step 2, introducing the mixed raw materials into a twin-screw extruder, extruding and granulating at a temperature of 175-205° C. to obtain a flame retardant material masterbatch; Step 3, placing the flame retardant material masterbatch in a mold for processing and molding, and finally obtaining an environmentally friendly flame retardant tube. Example 3

[0045] An environmentally friendly flame retardant tube, calculated by weight, comprising: 95 parts of polypropylene, 26 parts of maleic anhydride grafted polypropylene, 20 parts of activated calcium carbonate, 25 parts of environmentally friendly flame retardant, 4 parts of lubricant, 3 parts of antioxidant, 1.6 parts of light stabilizer and 2.4 parts of heat stabilizer.

[0046] The density of polypropylene is 0.947 g / cm3 , the melt index is 2.4g / 10min (190℃, 2.16kg); the grafting rate of maleic anhydride grafted polypropylene PP-g-MAH is 1%, and the density is 0.918g / cm 3 , the melt index is 65g / 10min (190℃, 2.16kg); the lubricant is oxidized polyethylene wax; the antioxidant is antioxidant 1076; the light stabilizer is light stabilizer 783; the heat stabilizer is dibutyltin bis(monooctyl maleate).

[0047] The preparation process of activated calcium carbonate includes: 5-8μm calcium carbonate powder and KH570 were mixed in an ethanol solution with a mass fraction of 30%-50%. The mass volume ratio of calcium carbonate powder, KH570 and ethanol solution was 1g:0.5g:20mL. The mixture was refluxed at 85°C for 10h. After the treatment, the solid was separated by centrifugation, washed three times with water and then vacuum dried to obtain activated calcium carbonate.

[0048] Wherein, the preparation method of the environmentally friendly flame retardant comprises: S1. Weigh zirconium phosphate powder (ZP) and 50wt% ethanol solution, mix them, fully disperse them in an ultrasonic disperser, add γ-mercaptopropylmethyldimethoxysilane, the mass volume ratio of zirconium phosphate powder, γ-mercaptopropylmethyldimethoxysilane and anhydrous ethanol is 10g:2.6g:100mL, stir in a 70°C water bath for 8h, after the reaction is completed, separate the solid and wash it with alcohol for at least three times, and dry it under vacuum to obtain thiolated zirconium phosphate (ZP-SH); S2. Weigh sulfadiazine (SD), triethylamine (TEA) and 0.6 mol / L sodium hydroxide solution and mix them in a beaker. The mass volume ratio of sulfadiazine, triethylamine and sodium hydroxide solution is 7.5 g:2 g:50 mL. Stir and disperse them evenly at room temperature to obtain a sulfadiazine mixed solution. Weigh 4-vinylbenzenesulfonyl chloride (p-VSCl) and acetone and mix them in a flask. Pass nitrogen as a protective gas. At room temperature, add the sulfadiazine mixed solution drop by drop at a dropping speed of 10 mL / m in, adding dropwise while stirring, the stirring speed is 450r / min, the mass volume ratio of the mixed solution of 4-vinylbenzenesulfonyl chloride, acetone and sulfadiazine is 6.3g:25mL:55mL, after the addition is completed, the temperature is raised to 90°C, refluxed and stirred for 20h, after the reaction is completed, the solvent is first removed by rotary evaporation, and then the product is washed with 5% saline solution until the washing liquid is neutral, and then washed with pure water three times, and dried under vacuum to obtain vinyl sulfonamidated sulfadiazine (VSN-SD); S3. Weigh zirconium thiophosphate (ZP-SH) and vinyl sulfonamidated sulfadiazine (VSN-SD) respectively and add them into dimethyl sulfoxide (DMSO). The mass volume ratio of zirconium thiophosphate, vinyl sulfonamidated sulfadiazine and DMSO is 1g:0.68g:25mL. Stir and disperse them evenly at room temperature. Add 8% of the mass of vinyl sulfonamidated sulfadiazine dimethyl ether (DMPA) as a photoinitiator at a wavelength of 365nm and a light intensity of 2.5mW / cm 2 The reaction was stirred for 1.5 hours under the irradiation of LED ultraviolet light. After the reaction was completed, the solvent was removed under reduced pressure to obtain an environmentally friendly flame retardant.

[0049] The method for preparing the above-mentioned environmentally friendly flame-retardant tube comprises the following steps: Step 1, weighing each raw material according to the weight, then mixing each raw material in a blender, and fully blending at a speed of 800 r / min to obtain a mixed raw material; Step 2, introducing the mixed raw materials into a twin-screw extruder, extruding and granulating at a temperature of 175-205° C. to obtain a flame retardant material masterbatch; Step 3, placing the flame retardant material masterbatch in a mold for processing and molding, and finally obtaining an environmentally friendly flame retardant tube.

[0050] Comparative Example 1 An environmentally friendly flame-retardant tube, which differs from Example 1 only in that the environmentally friendly flame retardant is replaced by zirconium phosphate powder (ZP).

[0051] Comparative Example 2 A flame-retardant composite material tube, which is different from Example 1 only in that the environmentally friendly flame retardant is replaced by vinyl sulfonamidation sulfadiazine (VSN-SD), and the preparation of vinyl sulfonamidation sulfadiazine is the same as that of Example 1.

[0052] Comparative Example 3 A flame retardant composite material tube, which differs from Example 1 only in that the environmentally friendly flame retardant is replaced by a mixture of zirconium phosphate powder (ZP) and vinyl sulfonamidated sulfadiazine (VSN-SD), and the mass ratio of the zirconium phosphate powder to the vinyl sulfonamidated sulfadiazine is 1:0.51.

[0053] Experimental example The composite material pipes prepared in Example 1 and Comparative Examples 1-3 were tested and compared in terms of performance. The relevant testing standards include: tensile strength with reference to ISO 527-2:2012, simply supported beam notched impact strength with reference to ISO 179-1:2010, limiting oxygen index with reference to ISO 4589-2:1996, flame retardant grade with reference to ANSI / UL-94-1985, UV aging treatment: with reference to GB / T 16422.3-2014, the material was subjected to 340nm, 0.76W / m 2 The samples were placed in a UVA-340 UV aging test chamber for 1500 hours in a cycle (8 hours of light, 4 hours of darkness), and then the change rates of tensile strength, flexural modulus and notched impact strength after aging were tested. The test results are shown in Table 1: Table 1 Performance test results of different environmentally friendly flame retardant tubes

[0054] It can be seen from Table 1 that the environmentally friendly flame-retardant tube prepared in Example 1 not only has excellent flame retardancy, but also maintains excellent mechanical properties and excellent aging resistance. In summary, it can be proved that the environmentally friendly flame-retardant tube prepared in the present invention has higher strength and better impact resistance than the traditional polypropylene flame-retardant tube, and the flame-retardant tube is more durable and has a longer service life, thereby reducing the replacement frequency and related maintenance costs.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed 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. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0056] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An environmentally friendly flame retardant tube, characterized in that: Calculated by weight, including: 75-95 parts of polypropylene, 13-26 parts of maleic anhydride grafted polypropylene, 10-20 parts of activated calcium carbonate, 15-25 parts of environmentally friendly flame retardant, 2-4 parts of lubricant, 1.5-3 parts of antioxidant, 0.8-1.6 parts of light stabilizer and 1.2-2.4 parts of heat stabilizer; The environmentally friendly flame retardant is prepared by combining vinyl sulfonamidated sulfadiazine and thiolated zirconium phosphate.

2. The environmentally friendly flame-retardant tube according to claim 1, characterized in that: The density of the polypropylene is 0.943-0.958 g / cm 3 The melt index is 1.2-3.6 g / 10 min at 190°C and 2.16 kg; the grafting rate of the maleic anhydride grafted polypropylene PP-g-MAH is 0.8-1.2%, and the density is 0.912-0.926 g / cm 3 , the melt index is 50-80 g / 10 min at 190°C and 2.16 kg.

3. The environmentally friendly flame-retardant tube according to claim 1, characterized in that: The activated calcium carbonate is calcium carbonate activated by a silane coupling agent; wherein the silane coupling agent is one of KH550, KH560 and KH570.

4. The environmentally friendly flame-retardant tube according to claim 1, characterized in that: The lubricant is a mixture of one or more of zinc stearate, calcium stearate, liquid paraffin, oxidized polyethylene wax, and ethylene bisstearamide; the antioxidant is a mixture of one or more of antioxidant 168, antioxidant 626, antioxidant 1076, and antioxidant 1010.

5. The environmentally friendly flame-retardant tube according to claim 1, characterized in that: The light stabilizer is a hindered amine light stabilizer, including a mixture of one or more of light stabilizer 622, light stabilizer 770, light stabilizer 783, and light stabilizer 944; the heat stabilizer is an organic tin heat stabilizer, including a mixture of one or more of dioctyltin dilaurate, dibutyltin maleate, dibutyltin bis(monobutyl maleate), dioctyltin maleate, and dibutyltin bis(monooctyl maleate).

6. The environmentally friendly flame-retardant tube according to claim 1, characterized in that: The preparation method of the environmentally friendly flame retardant comprises: S1. Weigh zirconium phosphate powder and ethanol solution, mix them, fully disperse them in an ultrasonic disperser, add a mercaptosilane coupling agent, stir them in a water bath at 60-80° C. for 5-10 hours, separate, wash and dry them after the reaction is completed to obtain mercapto zirconium phosphate ZP-SH; S2, weigh sulfadiazine, triethylamine and sodium hydroxide solution, mix them in a beaker, stir and disperse them evenly at room temperature to obtain a sulfadiazine mixed solution; weigh 4-vinylbenzenesulfonyl chloride and acetone, mix them in a flask, add the sulfadiazine mixed solution drop by drop, and after the addition is completed, heat it to 70-90° C., reflux and stir to react for 10-20 hours, and after the reaction is completed, remove the solvent, wash and dry to obtain vinyl sulfonamidated sulfadiazine; S3. Weigh thiolated zirconium phosphate and vinylsulfonamidated sulfadiazine separately, add them into dimethyl sulfoxide, stir and disperse them evenly at room temperature, add photoinitiator, stir and react for 0.5-1.5h under LED ultraviolet lamp, and after the reaction, remove the solvent under reduced pressure to obtain an environmentally friendly flame retardant.

7. The environmentally friendly flame-retardant tube according to claim 6, characterized in that: In S1, the mass volume ratio of zirconium phosphate powder, mercaptosilane coupling agent and anhydrous ethanol is 10g:(1.3-2.6)g:(50-100)mL; the mercaptosilane coupling agent is one or more of γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane and γ-mercaptopropylmethyldimethoxysilane.

8. The environmentally friendly flame-retardant tube according to claim 6, characterized in that: In the sulfadiazine mixed solution of S2, the concentration of the sodium hydroxide solution is 0.1-0.6 mol / L, and the mass volume ratio of sulfadiazine, triethylamine and sodium hydroxide solution is (2.5-7.5) g:(1-2) g:(30-50) mL; in S2, the mass volume ratio of 4-vinylbenzenesulfonyl chloride, acetone and sulfadiazine mixed solution is (2.1-6.3) g:(15-25) mL:(35-55) mL.

9. The environmentally friendly flame-retardant tube according to claim 6, characterized in that: In S3, the mass volume ratio of thiolated zirconium phosphate, vinylsulfonamidated sulfadiazine and dimethyl sulfoxide is 1 g: (0.34-0.68) g: (15-25) mL; the photoinitiator is benzoin dimethyl ether, and the added amount is 2%-8% of the mass of vinylsulfonamidated sulfadiazine.

10. A method for preparing the environmentally friendly flame-retardant tube according to claim 1, characterized in that: The following steps are involved: Step 1, weighing each raw material according to the weight, then mixing each raw material in a blender, and fully blending at a speed of 500-800 r / min to obtain a mixed raw material; Step 2, introducing the mixed raw materials into a twin-screw extruder, extruding and granulating at a temperature of 175-205° C. to obtain a flame retardant material masterbatch; Step 3, placing the flame retardant material masterbatch in a mold for processing and molding, and finally obtaining an environmentally friendly flame retardant tube.

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