Preparation method of halogen-free environment-friendly flame-retardant PVC cable

Abstract

The present application relates to a kind of halogen-free environmental protection flame-retardant PVC cable and preparation method, belong to PVC cable technical field.The present application provides a kind of halogen-free environmental protection flame-retardant PVC cable, its preparation steps are to obtain material one by compounding PVC, ATBC plasticizer and epoxy soybean oil, obtain material two by compounding material one, La-Zn composite rare earth stabilizer, polyether silicone oil, silicon carbide nanowire, obtain material three by compounding material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modification biochar, obtain mixed material by compounding material three and borate crosslinking agent, finally extrude mixed material on the surface of armored wire core, cooling forming.The present application uses diatomite-ammonium polyphosphate composite flame retardant, zinc borate and calcium stannate to replace traditional halogen-containing flame retardant, avoid releasing toxic hydrogen halide gas when burning, meet environmental protection requirement, on this basis, by the compounding of each component, synergistic effect of flame-retardant is played.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of PVC cables and relates to a preparation method of a halogen-free environment-friendly flame-retardant PVC cable. BACKGROUND

[0002] Cables are an indispensable important infrastructure measure in modern society, widely used in power transmission, communication networks and control systems and many other fields. According to different functions and structures, cables can be divided into network cables, electric wires and cables and other types, mainly used for efficient transmission of electric energy and information. Their normal operation is directly related to the smoothness and safety of social production and life. Although traditional cables have important functions in application, they also have many shortcomings in use. For example, traditional cables often use halogen-containing materials, which can release toxic gases in a fire, seriously affecting personal safety and environmental protection. In addition, the flame-retardant effect of some cables is insufficient, which cannot effectively inhibit the spread of fire, thereby causing greater property losses and casualties in high-temperature or fire conditions. These problems not only affect the safety and reliability of cables, but also pose a challenge to the sustainable development of the industry. SUMMARY

[0003] The purpose of the present application is to provide a preparation method of a halogen-free environment-friendly flame-retardant PVC cable. The present application uses diatomite-ammonium polyphosphate composite flame retardant, zinc borate and calcium stannate to replace traditional halogen-containing flame retardants, avoiding the release of toxic hydrogen halide gas during combustion, meeting environmental protection requirements. On this basis, the components are compounded to synergistically exert the flame-retardant effect.

[0004] The purpose of the present application can be achieved by the following technical solutions:

[0005] A preparation method of a halogen-free environment-friendly flame-retardant PVC cable, the preparation method of the PVC cable comprising the following steps:

[0006] Step one, mixing PVC, ATBC plasticizer and epoxy soybean oil to obtain material one;

[0007] Step two, adding La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowires to material one to obtain material two;

[0008] Step three, mixing material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to obtain material three;

[0009] Step four, adding borate ester crosslinking agent to material three to obtain a mixture;

[0010] Step five, extruding the mixture on the surface of the armored wire core and cooling to form.

[0011] Further, the mass ratio of the PVC, the ATBC plasticizer, and the epoxy soybean oil in step one is 1:0.26-0.3:0.06-0.08; the mixing method is to stir at a speed of 600-800 rpm for 5-7 min after being heated to 93-97℃.

[0012] Further, the mass ratio of the material one, the La-Zn composite rare earth stabilizer, the polyether silicone oil, and the silicon carbide nanowire in step two is 13.2-13.8:0.3-0.5:0.11-0.13:0.04-0.06; the mixing method is to stir at a speed of 800-900 rpm for 4-6 min.

[0013] Further, the preparation method of the La-Zn composite rare earth stabilizer in step two comprises the following steps:

[0014] In step X1, the lanthanum nitrate and the zinc nitrate are mixed according to a mass ratio of 1:3-4, and then the ammonia water with a mass concentration of 25-28wt% is added dropwise at a dropping speed of 2-5 mL / min to adjust the pH to 8-10 at a temperature of 60-80℃ and a stirring speed of 300-500 rpm, and then the mixture is left to stand for 2-3 h after the pH value is reached, and then the La-Zn hydroxide coprecipitate is obtained by filtration.

[0015] In step X2, the La-Zn hydroxide coprecipitate is calcined at 800-900℃ for 3-4 h to obtain the La-Zn composite oxide.

[0016] In step X3, the KH-550, the anhydrous ethanol, and the deionized water are mixed according to a volume ratio of 1:4-5:1, and then stirred at room temperature for 25-35 min, and then the 0.1M acetic acid solution is added dropwise to adjust the pH to 4-5 to obtain the silane solution.

[0017] In step X4, the La-Zn composite oxide and the silane solution are mixed according to a mass ratio of 1:6-10, and then stirred at 200-400 rpm for 2-4 h at a temperature of 50-60℃, and then filtered, precipitated, and dried, and then kept at a temperature of 120-130℃ for 1-1.2 h to obtain the composite rare earth stabilizer.

[0018] Further, the preparation method of the diatomite-ammonium polyphosphate composite flame retardant in step three comprises the following steps:

[0019] In step Y1, the diatomite is calcined at 340-360℃ for 1.5-2.5 h to obtain the active diatomite.

[0020] In step Y2, the active diatomite, the ammonium polyphosphate, and the anhydrous ethanol are mixed according to a mass ratio of 1:0.66-0.7:4.5-5.1, and then ball milled for 2-3 h, and then spray dried to obtain the diatomite-ammonium polyphosphate composite flame retardant.

[0021] Further, the mixing mode is that the diatomite-ammonium polyphosphate is divided into a first batch, a second batch and a third batch, the first batch and the second batch are added to the material two, and each time after stirring for 2-3 min, 2 min is interval, the third batch, zinc borate, calcium stannate and the coupling agent surface modified biochar are added at the same time, the temperature is increased to 102-108 DEG C, and stirring is carried out for 6-10 min, then the temperature is increased to 108-112 DEG C, and the rotating speed is increased to 950-1050 rpm, and stirring is carried out for 8-12 min.

[0022] Further, the mass ratio of the first batch, the second batch and the third batch is 9.5-10.1:1.18-1.22:0.64-0.68, the mass ratio of the first batch and the material two is 1:7.8-8.2, and the mass ratio of the third batch, zinc borate, calcium stannate and the coupling agent surface modified biochar is 1:5.8-6.2:3.5-4.5:5.2-5.4.

[0023] Further, the preparation method of the coupling agent surface modified biochar in step three comprises the following steps:

[0024] In an oxygen-free atmosphere, the rice husk is carbonized at 600-620 DEG C for 2.2-2.6 h to obtain biochar powder;

[0025] In step Z2, the biochar powder and a KH-550 ethanol solution with a mass concentration of 1.5-2.5 wt% of KH-550 are mixed according to a ratio of 1:10-12 g / mL, an ultrasonic frequency of 35-45 kHz, an ultrasonic power of 100-200 W and an ultrasonic temperature of 60 DEG C are set, and ultrasonic treatment is carried out for 1.8-2.2 h to obtain a mixed material.

[0026] In step Z3, the mixed material is purified, and the coupling agent surface modified biochar is obtained.

[0027] Further, the mass ratio of the material three and the borate crosslinking agent in step four is 17.3-17.5:0.38-0.42, and the treatment mode is that the temperature is reduced to 85-95 DEG C for stirring for 3-7 min, and the material is discharged after the temperature is reduced to 60 DEG C.

[0028] Further, the water temperature used during cooling in step five is 20-30 DEG C, and the water pressure is 0.2-0.4 MPa.

[0029] The beneficial effects of the present application are as follows:

[0030] (1) The diatomite-ammonium polyphosphate composite flame retardant, zinc borate and calcium stannate are used to replace the traditional halogen-containing flame retardant, so that the release of toxic hydrogen halide gas during combustion is avoided, and the environmental protection requirement is met.

[0031] (2) The diatomite is calcined to activate the surface thereof, the porous structure of the diatomite is used to adsorb ammonium polyphosphate, the decomposition of the ammonium polyphosphate is delayed, and the time of the flame-retardant effect is prolonged; the ammonium polyphosphate is decomposed to generate polyphosphoric acid, and the formation of the carbon layer is promoted; the flame retardant is added in batches to ensure uniform dispersion of the flame retardant and avoid agglomeration; on this basis, the zinc borate catalyzes the formation of the carbon, the calcium stannate inhibits ignition, and the ammonium polyphosphate forms gas phase-coagulation phase synergistic flame retardation; further, the coupling agent surface-modified biochar forms a dense carbon layer at high temperature to isolate oxygen and heat, and simultaneously adsorb free radicals generated during combustion; in addition, the La-Zn composite rare earth stabilizer is used to improve the thermal stability, and the silanization treatment is helpful to enhance the compatibility with PVC and reduce thermal degradation during processing; the components are processed in a specific manner to synergistically exert the flame-retardant effect. DETAILED DESCRIPTION

[0032] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with examples.

[0033] Example 1

[0034] A preparation method of a halogen-free and environmentally friendly flame-retardant PVC cable, the preparation method of the PVC cable of the present embodiment comprises the following steps:

[0035] Step one, mixing PVC, ATBC plasticizer and epoxy soybean oil to obtain material one;

[0036] Step two, adding La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowires to the material one to obtain material two;

[0037] Step three, mixing the material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface-modified biochar to obtain material three;

[0038] Step four, adding borate ester crosslinking agent to the material three to obtain a mixture;

[0039] Step five, extruding the mixture on the surface of the armored wire core and cooling to form.

[0040] The mass ratio of PVC, ATBC plasticizer and epoxy soybean oil in step one of the present embodiment is 1:0.26:0.06; the mixing mode is to stir at 600 rpm for 5 min after heating to 93℃.

[0041] The mass ratio of the material one, La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowires in step two of the present embodiment is 13.2:0.3:0.11:0.04; the mixing mode is to stir at 800 rpm for 4 min.

[0042] The preparation method of the La-Zn composite rare earth stabilizer in step two of the embodiment comprises the following steps:

[0043] In step X1, lanthanum nitrate and zinc nitrate are mixed in a mass ratio of 1:3, then ammonia water with a mass concentration of 25wt% is added dropwise at a dropping speed of 2mL / min to adjust the pH to 8 at 60°C and a rotation speed of 300rpm, and after the pH value is reached, the mixture is left to stand for 3h, filtered, and La-Zn hydroxide coprecipitate is obtained.

[0044] In step X2, the La-Zn hydroxide coprecipitate is calcined at 800°C for 4h to obtain La-Zn composite oxide.

[0045] In step X3, KH-550, anhydrous ethanol and deionized water are mixed in a volume ratio of 1:4:1, stirred at room temperature for 25min, and 0.1M acetic acid solution is added dropwise to adjust the pH to 4 to obtain a silane solution.

[0046] In step X4, the La-Zn composite oxide and the silane solution are mixed in a mass ratio of 1:6, stirred at 200rpm for 4h at 50°C, filtered, precipitated and dried, and heat treated at 120°C for 1.2h to obtain the composite rare earth stabilizer.

[0047] The preparation method of the diatomite-ammonium polyphosphate composite flame retardant in step three of the embodiment comprises the following steps:

[0048] In step Y1, diatomite is calcined at 340°C for 2.5h to obtain active diatomite.

[0049] In step Y2, the active diatomite, ammonium polyphosphate and anhydrous ethanol are mixed in a mass ratio of 1:0.66:4.5, ball milled for 2h, and spray dried to obtain the diatomite-ammonium polyphosphate composite flame retardant.

[0050] In the mixing method in step three of the embodiment, the diatomite-ammonium polyphosphate is divided into a first batch, a second batch and a third batch, the first batch and the second batch are added to the second material, and after the addition of the first batch and the second batch, the mixture is stirred for 2min each time, and after each stirring is completed, the mixture is left to stand for 2min, the third batch, zinc borate, calcium stannate and the coupling agent surface modified biochar are added at the same time, the temperature is raised to 102°C, the mixture is stirred for 6min, then the temperature is raised to 108°C and the rotation speed is increased to 950rpm, and the mixture is stirred for 12min.

[0051] The mass ratio of the first batch, the second batch and the third batch in the embodiment is 9.5:1.18:0.64; the mass ratio of the first batch and the second material is 1:7.8; and the mass ratio of the third batch, zinc borate, calcium stannate and the coupling agent surface modified biochar is 1:5.8:3.5:5.2.

[0052] The preparation method of the coupling agent surface modified biochar in step three of the embodiment comprises the following steps:

[0053] Step Z1, after carbonizing the rice husk at 600 DEG C for 2.6h in an oxygen-free atmosphere, biochar powder is obtained;

[0054] Step Z2, the biochar powder and the KH-550 ethanol solution with a mass concentration of 1.5wt% KH-550 are mixed in a ratio of 1:10g / mL, the ultrasonic frequency is set to 35kHz, the ultrasonic power is 100W, the ultrasonic temperature is 60 DEG C, and the mixture is obtained after ultrasonic treatment for 2.2h;

[0055] Step Z3, the mixture is purified, and the product is obtained.

[0056] In step four of the embodiment, the mass ratio of the material three, borate crosslinking agent, is 17.3:0.38; the treatment method is to cool to 85 DEG C and stir for 7min, and the material is discharged after the temperature drops to 60 DEG C.

[0057] In step five of the embodiment, the water temperature used for cooling is 20 DEG C, and the water pressure is 0.4MPa.

[0058] Example 2

[0059] A preparation method of a halogen-free and environmentally friendly flame-retardant PVC cable, the preparation method of the PVC cable of the embodiment comprises the following steps:

[0060] Step one, mix PVC, ATBC plasticizer and epoxy soybean oil to obtain material one;

[0061] Step two, add La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire to the material one to obtain material two;

[0062] Step three, mix the material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to obtain material three;

[0063] Step four, add borate crosslinking agent to the material three to obtain a mixture;

[0064] Step five, extrude the mixture on the surface of the armored wire core and cool to form.

[0065] In step one of the embodiment, the mass ratio of PVC, ATBC plasticizer and epoxy soybean oil is 1:0.27:0.068; the mixing method is to heat to 94 DEG C and stir at a speed of 640rpm for 6.7min.

[0066] The mass ratio of the material one, the La-Zn composite rare earth stabilizer, the polyether silicone oil and the silicon carbide nanowire in step two of the embodiment is 13.4:0.36:0.118:0.043; the mixing mode is stirring at a speed of 820 rpm for 5.5 min.

[0067] The preparation method of the La-Zn composite rare earth stabilizer in step two of the embodiment comprises the following steps:

[0068] In step X1, lanthanum nitrate and zinc nitrate are mixed according to a mass ratio of 1:3.2, then ammonia water with a mass concentration of 26wt% is added dropwise at a dropping speed of 3 mL / min to adjust the pH to 8.5 at 68℃ and a rotating speed of 350 rpm, and after the pH value is reached, the mixture is left to stand for 2.8 h, filtered, and the La-Zn hydroxide coprecipitate is obtained.

[0069] In step X2, the La-Zn hydroxide coprecipitate is calcined at 820℃ for 3.6 h to obtain the La-Zn composite oxide.

[0070] In step X3, KH-550, anhydrous ethanol and deionized water are mixed according to a volume ratio of 1:4.2:1, stirred at room temperature for 28 min, and 0.1M acetic acid solution is added dropwise to adjust the pH to 4.3 to obtain a silane solution.

[0071] In step X4, the La-Zn composite oxide and the silane solution are mixed according to a mass ratio of 1:7, stirred at 52℃ and a rotating speed of 250 rpm for 3.5 h, filtered, precipitated and dried, and heated at 122℃ for 1.05 h to obtain the composite rare earth stabilizer.

[0072] The preparation method of the diatomite-ammonium polyphosphate composite flame retardant in step three of the embodiment comprises the following steps:

[0073] In step Y1, diatomite is calcined at 345℃ for 2.2 h to obtain active diatomite.

[0074] In step Y2, the active diatomite, ammonium polyphosphate and anhydrous ethanol are mixed according to a mass ratio of 1:0.67:4.7, ball milled for 2.2 h, and spray dried to obtain the diatomite-ammonium polyphosphate composite flame retardant.

[0075] In step three of the embodiment, the diatomite-ammonium polyphosphate is divided into a first batch, a second batch and a third batch, the first batch and the second batch are added to the material two, and after the addition of the first batch and the second batch, the mixture is stirred for 2.2 min each time, and after each stirring is completed, the mixture is left to stand for 2 min, the third batch, zinc borate, calcium stannate and the coupling agent surface modified biochar are added at the same time, the temperature is raised to 104℃, the mixture is stirred for 9 min, then the temperature is raised to 109℃ and the rotating speed is increased to 980 rpm, and the mixture is stirred for 11 min.

[0076] The mass ratio of the first batch, the second batch and the third batch of the embodiment is 9.6:1.19:0.65; the mass ratio of the first batch and the material two is 1:7.9; the mass ratio of the third batch, zinc borate, calcium stannate and the coupling agent surface modified biochar is 1:5.9:3.8:5.25.

[0077] The preparation method of the coupling agent surface modified biochar in step three of the embodiment comprises the following steps:

[0078] Step Z1, in an oxygen-free atmosphere, rice husk is carbonized at 608℃ for 2.5h to obtain biochar powder;

[0079] Step Z2, the biochar powder and the KH-550 ethanol solution with a mass concentration of 1.8wt% KH-550 are mixed in a ratio of 1:10.6g / mL, the ultrasonic frequency is set to 38kHz, the ultrasonic power is 120W, the ultrasonic temperature is 60℃, and the ultrasonic time is 2.1h to obtain a mixture;

[0080] Step Z3, the mixture is purified, and the coupling agent surface modified biochar is obtained.

[0081] The mass ratio of the material three, the borate crosslinking agent in step four of the embodiment is 17.35:0.39; the treatment method is to cool to 88℃ and stir for 4min, and then take out the material when the temperature drops to 60℃.

[0082] The water temperature used in the cooling in step five of the embodiment is 22℃, and the water pressure is 0.4MPa.

[0083] Example 3

[0084] A preparation method of a halogen-free and environmentally friendly flame-retardant PVC cable, the preparation method of the PVC cable of the embodiment comprises the following steps:

[0085] Step one, mix PVC, ATBC plasticizer and epoxy soybean oil to obtain material one;

[0086] Step two, add La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire to the material one, and mix to obtain material two;

[0087] Step three, mix the material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to obtain material three;

[0088] Step four, add borate crosslinking agent to the material three to obtain a mixture;

[0089] Step five, extrude the mixture on the surface of the armored wire core and cool to form.

[0090] The mass ratio of PVC, ATBC plasticizer and epoxy soybean oil in step one of the embodiment is 1:0.28:0.07; the mixing mode is that stirring at 700 rpm for 6 min after heating to 95℃.

[0091] The mass ratio of material one, La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire in step two of the embodiment is 13.5:0.4:0.12:0.05; the mixing mode is stirring at 850 rpm for 5 min.

[0092] The preparation method of the La-Zn composite rare earth stabilizer in step two of the embodiment comprises the following steps:

[0093] Step X1, mix lanthanum nitrate and zinc nitrate according to the mass ratio of 1:3.5, then add 26.5wt% ammonia water at a dropping speed of 3.5 mL / min to adjust the pH to 9 at 70℃ and 400 rpm, and then stand for 2.5 h after reaching the pH value, filter to obtain La-Zn hydroxide coprecipitate;

[0094] Step X2, calcine the La-Zn hydroxide coprecipitate at 850℃ for 3.5 h to obtain La-Zn composite oxide;

[0095] Step X3, mix KH-550, anhydrous ethanol and deionized water according to the volume ratio of 1:4.5:1, stir at room temperature for 30 min, add 0.1M acetic acid solution to adjust the pH to 4.5 to obtain silane solution;

[0096] Step X4, mix the La-Zn composite oxide and the silane solution according to the mass ratio of 1:8, stir at 300 rpm for 3 h at 55℃, filter, precipitate and dry, and then heat at 125℃ for 1.1 h to obtain the composite rare earth stabilizer.

[0097] The preparation method of the diatomite-ammonium polyphosphate composite flame retardant in step three of the embodiment comprises the following steps:

[0098] Step Y1, calcine diatomite at 350℃ for 2 h to obtain active diatomite;

[0099] Step Y2, mix the active diatomite, ammonium polyphosphate and anhydrous ethanol according to the mass ratio of 1:0.68:4.8, ball mill for 2.5 h, and then spray dry to obtain the diatomite-ammonium polyphosphate composite flame retardant.

[0100] The mixing method in step three of the embodiment is that the diatomite-ammonium polyphosphate is divided into a first batch, a second batch and a third batch, the first batch and the second batch are added to the material two, and the stirring is performed for 2.5 min after the addition of the first batch and the second batch respectively. After each stirring is completed, the interval is 2 min. The zinc borate, calcium stannate and coupling agent surface modified biochar are added at the same time as the addition of the third batch. The temperature is increased to 105 DEG C, and the stirring is performed for 8 min. Then the temperature is increased to 110 DEG C, and the rotating speed is increased to 1000 rpm, and the stirring is performed for 10 min.

[0101] The mass ratio of the first batch, the second batch and the third batch of the embodiment is 9.8:1.2:0.66; the mass ratio of the first batch and the material two is 1:8; and the mass ratio of the third batch, the zinc borate, the calcium stannate and the coupling agent surface modified biochar is 1:6:4:5.3.

[0102] The preparation method of the coupling agent surface modified biochar in step three of the embodiment comprises the following steps:

[0103] In step Z1, the rice husk is carbonized at 610 DEG C for 2.4 h in an oxygen-free atmosphere to obtain biochar powder;

[0104] In step Z2, the biochar powder and a KH-550 ethanol solution with a mass concentration of 2wt% KH-550 are mixed according to a ratio of 1:11 g / mL. The ultrasonic frequency is 40 kHz, the ultrasonic power is 150 W, and the ultrasonic temperature is 60 DEG C. The mixing is ultrasonically treated for 2 h to obtain a mixed material.

[0105] In step Z3, the mixed material is purified to obtain the coupling agent surface modified biochar.

[0106] The mass ratio of the material three and the borate crosslinking agent in step four of the embodiment is 17.4:0.4. The treatment method is that the temperature is decreased to 90 DEG C, and the stirring is performed for 5 min. After the temperature is decreased to 60 DEG C, the material is discharged.

[0107] The water temperature used in the cooling in step five of the embodiment is 26 DEG C, and the water pressure is 0.3 MPa.

[0108] Embodiment 4

[0109] A preparation method of a halogen-free and environmentally friendly flame-retardant PVC cable, the preparation method of the PVC cable of the embodiment comprises the following steps:

[0110] In step one, the PVC, the ATBC plasticizer and the epoxy soybean oil are mixed to obtain a material one.

[0111] In step two, the La-Zn composite rare earth stabilizer, the polyether silicone oil and the silicon carbide nanowire are added to the material one, and the mixing is performed to obtain a material two.

[0112] Step three, mix the material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to obtain material three;

[0113] Step four, add borate crosslinking agent to the material three to obtain a mixture;

[0114] Step five, extrude the mixture on the surface of the armored wire core and cool to form.

[0115] The mass ratio of PVC, ATBC plasticizer and epoxy soybean oil in step one of the embodiment is 1:0.29:0.075; the mixing mode is to stir at 750 rpm for 5.5 min after heating to 96℃.

[0116] The mass ratio of material one, La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire in step two of the embodiment is 13.6:0.45:0.125:0.056; the mixing mode is to stir at 860 rpm for 4.5 min.

[0117] The preparation method of the La-Zn composite rare earth stabilizer in step two of the embodiment comprises the following steps:

[0118] Step X1, mix lanthanum nitrate and zinc nitrate according to a mass ratio of 1:3.6, then add 27wt% ammonia water at a dropping rate of 4mL / min to adjust the pH to 9.4 at 75℃ and 450 rpm, and then stand for 2.2h after reaching the pH value, filter to obtain La-Zn hydroxide coprecipitate;

[0119] Step X2, calcine the La-Zn hydroxide coprecipitate at 870℃ for 3.2h to obtain La-Zn composite oxide;

[0120] Step X3, mix KH-550, anhydrous ethanol and deionized water according to a volume ratio of 1:4.6:1, stir at room temperature for 32 min, add 0.1M acetic acid solution to adjust the pH to 4.7 to obtain a silane solution;

[0121] Step X4, mix the La-Zn composite oxide and the silane solution according to a mass ratio of 1:6-10, stir at 58℃ and 350 rpm for 2.4h, filter, precipitate and dry, and then heat at 128℃ for 1.16h to obtain a composite rare earth stabilizer.

[0122] The preparation method of the diatomite-ammonium polyphosphate composite flame retardant in step three of the embodiment comprises the following steps:

[0123] Step Y1, calcine diatomite at 355℃ for 1.8h to obtain active diatomite;

[0124] Step Y2, the active diatomite, ammonium polyphosphate and anhydrous ethanol were mixed according to the mass ratio of 1:0.69:5, ball-milled for 2.8h, and spray-dried to obtain the product.

[0125] In step three of the embodiment, the diatomite-ammonium polyphosphate was divided into a first batch, a second batch and a third batch, the first batch and the second batch were added to the material two, and the stirring was performed for 2.6min after the addition of the first batch and the second batch, respectively. After each stirring, the interval was 2min. The zinc borate, calcium stannate and the coupling agent surface modified biochar were added at the same time as the addition of the third batch. The temperature was increased to 106℃, and the stirring was performed for 7min. Then, the temperature was increased to 111℃, and the stirring speed was increased to 1020rpm. The stirring was performed for 9min.

[0126] In the embodiment, the mass ratio of the first batch, the second batch and the third batch was 9.9:1.21:0.67. The mass ratio of the first batch and the material two was 1:8.1. The mass ratio of the third batch, the zinc borate, the calcium stannate and the coupling agent surface modified biochar was 1:6.1:4.2:5.36.

[0127] The preparation method of the coupling agent surface modified biochar in step three of the embodiment comprises the following steps:

[0128] Step Z1, in an oxygen-free atmosphere, the rice husk was carbonized at 615℃ for 2.3h to obtain biochar powder;

[0129] Step Z2, the biochar powder and the KH-550 ethanol solution with a mass concentration of 2.2wt% of KH-550 were mixed according to the ratio of 1:11.2g / mL. The ultrasonic frequency was set to 42kHz, the ultrasonic power was set to 180W, and the ultrasonic temperature was set to 60℃. The mixture was ultrasonically treated for 1.9h to obtain a mixed material.

[0130] Step Z3, the mixed material was purified to obtain the product.

[0131] In step four of the embodiment, the mass ratio of the material three and the borate crosslinking agent was 17.45:0.41. The treatment was performed by reducing the temperature to 92℃ and stirring for 4min. After the temperature was reduced to 60℃, the material was discharged.

[0132] In step five of the embodiment, the water temperature used for cooling was 28℃, and the water pressure was 0.2MPa.

[0133] Example 5

[0134] A preparation method of a halogen-free and environmentally friendly flame-retardant PVC cable, the preparation method of the PVC cable in the embodiment comprises the following steps:

[0135] Step one, the PVC, the ATBC plasticizer and the epoxy soybean oil were mixed to obtain a material one.

[0136] Step two, add La-Zn composite rare earth stabilizer, polyether silicone oil, silicon carbide nanowires to material one to obtain material two;

[0137] Step three, mix material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to obtain material three;

[0138] Step four, add borate crosslinking agent to material three to obtain the mixture;

[0139] Step five, extrude the mixture on the surface of the armored wire core and cool to form.

[0140] The mass ratio of PVC, ATBC plasticizer and epoxy soybean oil in step one of the embodiment is 1:0.3:0.08; the mixing mode is to stir at 800 rpm for 5 min after heating to 97℃.

[0141] The mass ratio of material one, La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowires in step two of the embodiment is 13.8:0.5:0.13:0.06; the mixing mode is to stir at 900 rpm for 4 min.

[0142] The preparation method of La-Zn composite rare earth stabilizer in step two of the embodiment comprises the following steps:

[0143] Step X1, mix lanthanum nitrate and zinc nitrate in a mass ratio of 1:4, then add 28wt% ammonia water at a dropping rate of 5mL / min to adjust the pH to 10 at 80℃ and 500rpm, stand for 2h after reaching the pH value, filter to obtain La-Zn hydroxide coprecipitate;

[0144] Step X2, calcine the La-Zn hydroxide coprecipitate at 900℃ for 3h to obtain La-Zn composite oxide;

[0145] Step X3, mix KH-550, anhydrous ethanol and deionized water in a volume ratio of 1:5:1, stir at room temperature for 35min, add 0.1M acetic acid solution to adjust the pH to 5 to obtain silane solution;

[0146] Step X4, mix La-Zn composite oxide and silane solution in a mass ratio of 1:6-10, stir at 400rpm for 2h at 60℃, filter, precipitate and dry, and heat at 130℃ for 1h to obtain composite rare earth stabilizer.

[0147] The preparation method of diatomite-ammonium polyphosphate composite flame retardant in step three of the embodiment comprises the following steps:

[0148] Step Y1, after calcining diatomite at 360℃ for 1.5h, active diatomite was obtained;

[0149] Step Y2, after mixing active diatomite, ammonium polyphosphate and anhydrous ethanol according to the mass ratio of 1:0.7:5.1, ball milling for 3h, spray drying, it was obtained.

[0150] The mixing mode in step three of this example is to divide the diatomite-ammonium polyphosphate composite flame retardant into first batch, second batch and third batch, add the first batch and the second batch to the material two, respectively stir for 3min after adding the first batch and the second batch, interval 2min after each stirring, add the third batch at the same time, add zinc borate, calcium stannate and coupling agent surface modified biochar, increase the temperature to 108℃, stir for 6min, then increase the temperature to 112℃ and increase the speed to 1050rpm, stir for 8min.

[0151] The mass ratio of the first batch, the second batch and the third batch of this example is 10.1:1.22:0.68; the mass ratio of the first batch and the material two is 1:8.2; the mass ratio of the third batch, zinc borate, calcium stannate and coupling agent surface modified biochar is 1:6.2:4.5:5.4.

[0152] The preparation method of the coupling agent surface modified biochar in step three of this example comprises the following steps:

[0153] Step Z1, in an oxygen-free atmosphere, after carbonizing rice husk at 620℃ for 2.2h, biochar powder was obtained;

[0154] Step Z2, mix biochar powder and KH-550 ethanol solution with a mass concentration of 2.5wt% KH-550 according to the ratio of 1:12g / mL, set the ultrasonic frequency to 45kHz, the ultrasonic power to 200W and the ultrasonic temperature to 60℃, ultrasonic for 1.8h, to obtain the mixture;

[0155] Step Z3, purify the mixture, and it is obtained.

[0156] The mass ratio of the material three and the borate crosslinking agent in step four of this example is 17.5:0.42; the treatment mode is to reduce the temperature to 95℃ and stir for 3min, and then take out the material after the temperature is reduced to 60℃.

[0157] The water temperature used in the cooling in step five of this example is 30℃, and the water pressure is 0.2MPa.

[0158] Example 6

[0159] On the basis of example 3, remove the diatomite-ammonium polyphosphate composite flame retardant in step three, replace it with an equal weight of zinc borate, and keep other conditions consistent with example 3.

[0160] Example 7

[0161] On the basis of Example 3, remove zinc borate in step three, replace with equal weight of calcium stannate, other conditions remain the same as Example 3.

[0162] Example 8

[0163] On the basis of Example 3, remove calcium stannate in step three, replace with equal weight of coupling agent surface modified biochar, other conditions remain the same as Example 3.

[0164] Example 9

[0165] On the basis of Example 3, remove coupling agent surface modified biochar in step three, replace with equal weight of diatomite-polyammonium phosphate composite flame retardant, other conditions remain the same as Example 3.

[0166] Comparative Example 1

[0167] On the basis of Example 3, keep other conditions consistent, change the preparation method of PVC cable to the following steps:

[0168] Step one, mix PVC, ATBC plasticizer and epoxy soybean oil to get material one;

[0169] Step two, add La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire to material one, mix to get material two;

[0170] Step three, add diatomite-polyammonium phosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to material two, stir at 850 rpm for 5 min, heat to 105℃, stir for 8 min, then heat to 110℃ and increase the stirring speed to 1000 rpm, stir for 10 min, to get material three;

[0171] Step four, add borate crosslinking agent to material three, process to get the mixture;

[0172] Step five, extrude the mixture on the surface of the armored wire core and cool to shape.

[0173] Comparative Example 2

[0174] On the basis of Example 3, keep other conditions consistent, change the preparation method of PVC cable to the following steps:

[0175] Step one, mix PVC, ATBC plasticizer and epoxy soybean oil to get material one;

[0176] Step two, add La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire to material one, mix to get material two;

[0177] Step three, add diatomite-polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to material two, stir at 850 rpm for 5 min, heat to 110 DEG C, stir at 1000 rpm for 18 min, to obtain material three;

[0178] Step four, add borate crosslinking agent to material three to obtain a mixture;

[0179] Step five, extrude the mixture on the surface of the armored wire core and cool to form.

[0180] Comparative example 3

[0181] On the basis of example 3, keeping other conditions unchanged, the preparation method of PVC cable is changed to the following steps:

[0182] Step one, mix PVC, ATBC plasticizer and epoxy soybean oil to obtain material one;

[0183] Step two, divide diatomite-polyphosphate into first batch, second batch and third batch, add the first batch and the second batch to material one, respectively stir for 2.5 min after adding the first batch and the second batch, interval 2 min after each stirring, add zinc borate, calcium stannate and coupling agent surface modified biochar at the same time as adding the third batch, heat to 105 DEG C, stir for 8 min, then heat to 110 DEG C and increase the stirring speed to 1000 rpm, stir for 10 min, to obtain material two;

[0184] Step three, add La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire to material two to obtain material three; the mixing method is stirring at 850 rpm for 5 min;

[0185] Step four, add borate crosslinking agent to material three to obtain a mixture;

[0186] Step five, extrude the mixture on the surface of the armored wire core and cool to form.

[0187] Comparative example 4

[0188] On the basis of example 3, keeping other conditions unchanged, the preparation method of PVC cable is changed to the following steps:

[0189] The PVC, ATBC plasticizer, epoxy soybean oil, La-Zn composite rare earth stabilizer, polyether silicone oil, silicon carbide nanowire, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar are mixed, then heated to 110 DEG C, stirred at 1000 rpm for 34 min, then borate crosslinking agent is added, the temperature is reduced to 90 DEG C and stirred for 5 min, then the temperature is reduced to 60 DEG C, and the material is discharged and extruded on the surface of the armored wire core, and then cooled and formed.

[0190] Comparative example 5

[0191] On the basis of example 3, other conditions remain unchanged, the preparation method of diatomite-ammonium polyphosphate composite flame retardant is changed to the following steps:

[0192] The diatomite, ammonium polyphosphate and anhydrous ethanol are mixed according to the mass ratio of 1:0.68:4.8, then ball milled for 2.5 h, and then spray dried to obtain the product.

[0193] Comparative example 6

[0194] On the basis of example 3, other conditions remain unchanged, the coupling agent surface modified biochar is replaced by biochar, and the preparation method of biochar is as follows:

[0195] In an oxygen-free atmosphere, the rice husk is carbonized at 610 DEG C for 2.4 h to obtain biochar.

[0196] The PVC cables prepared in examples 1-9 and comparative examples 1-6 are used as samples, and their flame retardant properties are tested according to GB / T18380.32-2022, and the results are shown in the following table 1.

[0197] Table 1

[0198]

[0199]

[0200] As shown in table 1, the halogen-free and environmentally friendly flame-retardant PVC cable prepared by the present application has good flame-retardant properties, and has good application prospect in network cable, electric wire and cable and other types of cable.

[0201] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the present application, and any indirect modification, equivalent change and modification of the above examples according to the technical essence of the present application are still within the scope of the present application.

Claims

1. A method for preparing a halogen-free, environmentally friendly, flame-retardant PVC cable, characterized in that: The preparation method of the PVC cable comprises the following steps: Step one, mix PVC, ATBC plasticizer and epoxy soybean oil to obtain material one; Step two, add La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire into the material one to obtain material two; Step three, mix the material two, diatomite-ammonium polyphosphate composite flame retardant, zinc borate, calcium stannate and coupling agent surface modified biochar to obtain material three; Step four, add borate crosslinking agent into the material three to obtain mixed material; Step five, extrude the mixed material on the surface of the armored wire core and cool to form; The preparation method of the La-Zn composite rare earth stabilizer comprises the following steps: Step X1, mix lanthanum nitrate and zinc nitrate according to the mass ratio of 1:3-4, then drop 2-5 mL / min of ammonia water with a mass concentration of 25-28 wt% at 60-80℃ and a rotating speed of 300-500 rpm to adjust the pH value to 8-10, and then stand for 2-3 h after reaching the pH value, filter to obtain La-Zn hydroxide coprecipitate; Step X2, calcine the La-Zn hydroxide coprecipitate at 800-900℃ for 3-4 h to obtain La-Zn composite oxide; Step X3, mix KH-550, anhydrous ethanol and deionized water according to the volume ratio of 1:4-5:1, stir at room temperature for 25-35 min, drop 0.1M acetic acid solution to adjust the pH value to 4-5 to obtain silane solution; Step X4, mix the La-Zn composite oxide and the silane solution according to the mass ratio of 1:6-10, stir at 50-60℃ and a rotating speed of 200-400 rpm for 2-4 h, filter, precipitate and dry, and keep at 120-130℃ for 1-1.2 h to obtain La-Zn composite rare earth stabilizer; The preparation method of the diatomite-ammonium polyphosphate composite flame retardant in step three comprises the following steps: Step Y1, calcine diatomite at 340-360℃ for 1.5-2.5 h to obtain active diatomite; Step Y2, mix the active diatomite, ammonium polyphosphate and anhydrous ethanol according to the mass ratio of 1:0.66-0.7:4.5-5.1, ball mill for 2-3 h, and spray dry to obtain the diatomite-ammonium polyphosphate composite flame retardant; The preparation method of the coupling agent surface modified biochar in step three comprises the following steps: Step Z1, in an oxygen-free atmosphere, carbonize rice husk at 600-620℃ for 2.2-2.6 h to obtain biochar powder; Step Z2, mix the biochar powder and KH-550 ethanol solution with a mass concentration of 1.5-2.5 wt% of KH-550 according to the ratio of 1:10-12 g / mL, set the ultrasonic frequency to 35-45 kHz, the ultrasonic power to 100-200 W and the ultrasonic temperature to 60℃, and ultrasonic for 1.8-2.2 h to obtain mixed material; Step Z3, purify the mixed material to obtain the coupling agent surface modified biochar.

2. The preparation method of the halogen-free environment-friendly flame-retardant PVC cable according to claim 1, characterized in that: The mass ratio of PVC, ATBC plasticizer and epoxy soybean oil in step one is 1:0.26-0.3:0.06-0.08; the mixing mode is to heat to 93-97℃ and stir at a rotating speed of 600-800 rpm for 5-7 min.

3. The preparation method of the halogen-free environment-friendly flame-retardant PVC cable according to claim 1, characterized in that: The mass ratio of the material one, La-Zn composite rare earth stabilizer, polyether silicone oil and silicon carbide nanowire in step two is 13.2-13.8:0.3-0.5:0.11-0.13:0.04-0.06; the mixing mode is stirring at a speed of 800-900 rpm for 4-6 min.

4. The preparation method of the halogen-free environment-friendly flame-retardant PVC cable according to claim 1, characterized in that: The mixing mode in step three is that the diatomite-ammonium polyphosphate composite flame retardant is divided into first batch, second batch and third batch, the first batch and the second batch are added into the material two, and stirring is carried out for 2-3 min after the addition of the first batch and the second batch respectively, 2 min interval is set after each stirring, the third batch, zinc borate, calcium stannate and coupling agent surface modified biochar are added at the same time, the temperature is increased to 102-108 ℃, and stirring is carried out for 6-10 min, then the temperature is increased to 108-112 ℃, the speed is increased to 950-1050 rpm, and stirring is carried out for 8-12 min.

5. The preparation method of the halogen-free environment-friendly flame-retardant PVC cable according to claim 4, characterized in that: The mass ratio of the first batch, the second batch and the third batch is 9.5-10.1:1.18-1.22:0.64-0.68; the mass ratio of the first batch and the material two is 1:7.8-8.2; the mass ratio of the third batch, zinc borate, calcium stannate and coupling agent surface modified biochar is 1:5.8-6.2:3.5-4.5:5.2-5.

4.

6. The preparation method of the halogen-free environment-friendly flame-retardant PVC cable according to claim 1, characterized in that: The mass ratio of the material three and borate crosslinking agent in step four is 17.3-17.5:0.38-0.42; the treatment mode is stirring at 85-95 ℃ for 3-7 min, and the material is discharged after the temperature is reduced to 60 ℃.

7. The preparation method of the halogen-free environment-friendly flame-retardant PVC cable according to claim 1, characterized in that: The water temperature used in the cooling in step five is 20-30 ℃, and the water pressure is 0.2-0.4 MPa.

Images