Carbon nanotube-based polyvinyl chloride conductive master batch, and preparation method and application thereof

Abstract

The application discloses carbon nanotube-based polyvinyl chloride conductive master batch and a preparation method and application thereof. The preparation raw material of the polyvinyl chloride conductive master batch comprises the following components: carbon nanotube prepolymer, polyvinyl chloride resin, impact modifier and stabilizer, wherein the carbon nanotube prepolymer is prepared from carbon nanotubes, plasticizer, lubricant and dispersant. The carbon nanotube-based polyvinyl chloride conductive master batch provided by the application has the advantages of simple preparation process, green environmental protection, pretreatment of carbon nanotubes by adding plasticizer and dispersant, easy dispersion of carbon nanotubes in polyvinyl chloride and no precipitation of carbon nanotubes. In addition, the conductive master batch has low addition amount, excellent performance, can be widely applied to polyvinyl chloride products and has important commercial value.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of polyvinyl chloride conductive master batch, specifically to a kind of polyvinyl chloride conductive master batch based on carbon nanotube and its preparation method and application, belong to conductive plastic technical field. BACKGROUND

[0002] Polyvinyl chloride is a kind of plastic resin with very large amount, is widely used in medical, chemical, machinery manufacturing, aerospace and other fields. Insulation is the universal feature of PVC as plastic, in certain specific application scenarios, such as coal mine conveying device, chemical plant storage tank and waste gas ventilation duct, etc., insulation will be a dangerous factor of safety accident, therefore, PVC needs to be antistatic modified, so as to timely transfer charge in specific conditions. Carbon nanotube is a kind of filler with excellent conductivity / thermal conductivity and strong stability, which can make polyvinyl chloride product have certain charge transfer capacity under very small amount of addition, and will not affect the mechanical properties of the body. But because carbon nanotube is easy to fly in the air in the process of use, it will cause harm to the health of operators, and it is not easy to disperse in high viscosity polyvinyl chloride melt, so its production and application exist certain difficulty.

[0003] CN117165041A mixes one of carbon black, graphene, carbon nanotube and black phosphorus by ball milling, adds the obtained composite material into TX-100 solution, removes the solvent after mixing to obtain a composite conductive medium, and then performs blending extrusion and granulation with PET polyester dispersant and PET-PEG copolyester. The method involves the use and volatilization of a large amount of organic solvents, and carbon black, graphene and carbon nanotube cannot be well combined with the dispersant. In addition to the harm to the environment, it is also difficult to achieve good dispersion effect.

[0004] CN110564113A sets up a strong magnetic field outside a sealed container, mixes and stirs graphene, carbon nanotube, metal powder, metal oxide powder, conductive carbon black and base material by magnetic force, and then uses a single screw extrusion device to granulate. The magnetic field and mechanical stirring are essentially shear mixing by external force, and cannot achieve good dispersion effect. Moreover, the easily flying powders such as graphene, carbon nanotube and conductive carbon black are not treated during operation, which is not conducive to the health of production operators. SUMMARY

[0005] The main purpose of the present application is to provide a kind of polyvinyl chloride conductive master batch based on carbon nanotube and its preparation method, to solve any of the above and other potential problems in prior art.

[0006] Another purpose of the present application is also to provide the application of the polyvinyl chloride conductive master batch based on carbon nanotube.

[0007] To achieve the aforementioned technical purpose, the technical scheme adopted by the present application comprises:

[0008] The embodiment of the present application provides a kind of polyvinyl chloride conductive master batch based on carbon nanotube, and the raw materials for preparing the polyvinyl chloride conductive master batch include the following components: carbon nanotube prepolymer, polyvinyl chloride resin, impact modifier and stabilizer, wherein the carbon nanotube prepolymer is prepared by carbon nanotube, plasticizer, lubricant and dispersant.

[0009] In some embodiments, the carbon nanotube prepolymer is prepared by the following components in mass fraction: carbon nanotube 20% to 40%, plasticizer 50% to 80%, lubricant 1% to 5% and dispersant 0.2% to 5%.

[0010] In some embodiments, the raw materials for preparing the polyvinyl chloride conductive master batch include the following components in mass fraction: carbon nanotube prepolymer 30% to 50%, polyvinyl chloride resin 40% to 80%, impact modifier 1% to 5% and stabilizer 0.5% to 2%.

[0011] The embodiment of the present application also provides the preparation method of the aforementioned polyvinyl chloride conductive master batch based on carbon nanotube, which comprises:

[0012] The carbon nanotube, plasticizer, lubricant and dispersant are mixed uniformly and ground to prepare carbon nanotube prepolymer;

[0013] The carbon nanotube prepolymer, polyvinyl chloride resin, stabilizer and impact modifier are mixed uniformly, and then the obtained mixture is subjected to melt blending extrusion granulation to prepare the polyvinyl chloride conductive master batch based on carbon nanotube.

[0014] The embodiment of the present application also provides the application of the polyvinyl chloride conductive master batch based on carbon nanotube in preparing polyvinyl chloride product.

[0015] Correspondingly, the embodiment of the present application also provides a polyvinyl chloride product prepared from the aforementioned polyvinyl chloride conductive master batch based on carbon nanotube, and the content of carbon nanotube in the polyvinyl chloride product is 1wt% to 5wt%.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1) The present invention mixes a plasticizer, a dispersant, a lubricant, and carbon nanotubes and then grinds them to preliminarily disperse the carbon nanotubes. The dispersant and the carbon nanotubes are then combined, which facilitates uniform dispersion of the carbon nanotubes in the polyvinyl chloride resin. Furthermore, a plasticizer having good compatibility with the carbon nanotubes is used as a carrier between the polyvinyl chloride resin and the carbon nanotubes, thereby avoiding problems such as precipitation and uneven dispersion caused by poor compatibility between the carbon nanotubes and the polyvinyl chloride resin. The use of the plasticizer for impregnation also avoids the problem of powder flying during use of the carbon nanotubes. Furthermore, the plasticizer is non-volatile, low-toxic, and highly stable, making the preparation process environmentally friendly, simple, and feasible.

[0018] 2) The polyvinyl chloride conductive masterbatch prepared by the present invention has a low addition amount and good carbon nanotube dispersion. The prepared polyvinyl chloride product has a smooth surface, no blooming and no oil, and has important commercial value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 is a schematic diagram of the appearance of the carbon nanotube prepolymer prepared in Example 8 of the present invention;

[0021] Figure 2 Schematic diagram of the appearance of polyvinyl chloride conductive masterbatch prepared in Example 8 of the present invention;

[0022] Figure 3 This is a brittle cross-section diagram of the modified polyvinyl chloride product obtained in Example 8 of the present invention;

[0023] Figure 4 This is a brittle cross-section diagram of the polyvinyl chloride modified product obtained in Example 3. DETAILED DESCRIPTION

[0024] In light of the aforementioned problems in the prior art, the inventors of the present invention, after extensive and in-depth research, have developed a carbon nanotube-based polyvinyl chloride (PVC) conductive masterbatch and a method for preparing the same. The conductive masterbatch comprises carbon nanotubes, a plasticizer, a dispersant, a lubricant, PVC resin powder, an impact modifier, and a stabilizer. This technical solution, its implementation process, and principles are further explained below.

[0025] As an aspect of the technical solution of the present application, the preparation raw material of the polyvinyl chloride conductive master batch based on carbon nanotubes comprises the following components: carbon nanotube prepolymer, polyvinyl chloride resin, impact modifier and stabilizer, wherein the carbon nanotube prepolymer is prepared from carbon nanotubes, plasticizer, lubricant and dispersant.

[0026] In some embodiments, the carbon nanotube prepolymer is prepared from the following components in terms of mass fraction: carbon nanotubes 20% to 40%, plasticizer 50% to 80%, lubricant 1% to 5% and dispersant 0.2% to 5%.

[0027] In some embodiments, the plasticizer can include at least any one of diethylene glycol bis-octyl phthalate, epoxy soybean oil, acetyl tri-butyl citrate, diisononyl cyclohexane-1,2-dicarboxylate, but not limited to this. The plasticizer is directly used as a dispersing carrier in the present application, which improves the dispersion effect of carbon nanotubes and does not pollute the environment. It is also beneficial to the processability of the master batch. Further, the plasticizer is an environmentally friendly plasticizer, which can improve the compatibility between carbon nanotubes and polyvinyl chloride resin, and help the dispersion effect of carbon nanotubes in polyvinyl chloride resin.

[0028] In some embodiments, the lubricant can include at least any one of oxidized polyethylene wax, calcium stearate, polyol ester, methyl phenyl silicone oil, but not limited to this.

[0029] In some embodiments, the dispersant can include at least any one of dimethyl diallyl ammonium chloride-acrylic acid copolymer, octylphenol polyoxyethylene ether, sodium carboxymethyl cellulose, modified styrene maleic acid copolymer, etc., but not limited to this.

[0030] In some embodiments, the preparation raw material of the polyvinyl chloride conductive master batch comprises the following components in terms of mass fraction: carbon nanotube prepolymer 30% to 50%, polyvinyl chloride resin 40% to 80%, impact modifier 1% to 5% and stabilizer 0.5% to 2%.

[0031] In some embodiments, the impact modifier can include at least any one of methyl methacrylate-acrylate copolymer (ACR), methyl methacrylate-butadiene-styrene terpolymer (ABS), styrene-butadiene triblock copolymer (SBS), ethylene-vinyl acetate copolymer (EVA), but not limited to this. The addition of the impact modifier in the present application is helpful to the processability and mechanical properties of the master batch. In addition, improper selection of the impact modifier can have a negative impact on the dispersion of carbon nanotubes. The impact modifier selected in the present application has little negative impact on the dispersion of carbon nanotubes, and even has a positive impact.

[0032] In some embodiments, the stabilizer can include at least any one of zinc stearate, calcium stearate, rare earth stearate, triphenyl phosphite, di-n-octyltin isooctyl dimercaptate, etc., but not limited thereto.

[0033] As another aspect of the technical solution of the present application, a preparation method of a carbon nanotube-based polyvinyl chloride conductive master batch includes:

[0034] The carbon nanotubes, plasticizer, lubricant and dispersant are mixed uniformly and ground to prepare a carbon nanotube prepolymer.

[0035] The carbon nanotube prepolymer, polyvinyl chloride resin, stabilizer and impact modifier are mixed uniformly, and then the obtained mixture is subjected to melt blending extrusion and granulation to prepare the carbon nanotube-based polyvinyl chloride conductive master batch.

[0036] In some embodiments, the preparation process of the carbon nanotube prepolymer includes: the carbon nanotubes, plasticizer, lubricant and dispersant are mixed uniformly and ground by a three-roll grinder to prepare a carbon nanotube prepolymer. In the present application, the plasticizer, dispersant, lubricant and carbon nanotubes are mixed and then treated by a three-roll grinder, which preliminarily disperses the carbon nanotubes and combines the dispersant and carbon nanotubes together, thereby facilitating the uniform dispersion of the carbon nanotubes in the polyvinyl chloride resin. Meanwhile, the plasticizer with good compatibility with the carbon nanotubes is used as a carrier between the polyvinyl chloride resin and the carbon nanotubes, which avoids the problems of precipitation and uneven dispersion caused by the poor compatibility between the carbon nanotubes and the polyvinyl chloride resin.

[0037] Further, the carbon nanotubes are preliminarily dispersed by the three-roll grinder with the use of the plasticizer for infiltration, which also avoids the problem of easy flying of the carbon nanotube powder during use. Moreover, the plasticizer used is not easy to volatilize, has low toxicity and good stability, and the preparation process is green, simple and feasible.

[0038] Further, the three-roll grinding used in the pretreatment method of the present application is a new method in the field of master batch preparation, which is different from ball milling or high-speed stirring. The three-roll grinding can effectively combine the plasticizer, lubricant, dispersant and carbon nanotubes, thereby improving the dispersion effect of the carbon nanotubes in the polyvinyl chloride resin.

[0039] In some more specific embodiments, the grinding includes: sequentially passing through the horizontal feeding roller, the middle roller and the discharging roller to achieve the grinding and dispersion effect by the mutual extrusion and friction of the surfaces of the horizontal feeding roller, the middle roller and the discharging roller, wherein the spacing between the feeding roller, the middle roller and the discharging roller is 5-80 μm, the rotation speed of the rollers is 50-300 rpm, and the grinding passes are 3N6 times.

[0040] In some embodiments, the preparation method specifically comprises: mixing the carbon nanotube prepolymer, the polyvinyl chloride resin, the stabilizer and the impact modifier uniformly by using a high-speed mixer.

[0041] Specifically, the high-speed mixer has a rotation speed of 200-1000 rpm, a mixing temperature of 50-80℃ and a mixing time of 10-30 min.

[0042] In some embodiments, the preparation method specifically comprises: inputting the mixture into a twin-screw extruder for melt blending extrusion granulation; wherein the temperature of the twin-screw extruder is 160-200℃ and the screw rotation speed is 50-600 rpm.

[0043] In some more specific embodiments, the preparation method of the carbon nanotube-based polyvinyl chloride conductive masterbatch specifically comprises: mixing the plasticizer, the dispersant and the lubricant uniformly, then adding the carbon nanotubes, and after sufficient infiltration, using a three-roll mill for preliminary dispersion to prepare a carbon nanotube prepolymer; using a high-speed mixer to mix the prepolymer and the polyvinyl chloride resin powder, the impact modifier and the stabilizer uniformly, and using a twin-screw extruder to extrude and granulate the obtained mixture. This preparation process is simple, green and environmentally friendly, and the addition of plasticizer and dispersant for pretreatment of carbon nanotubes makes the carbon nanotubes more easily dispersed in polyvinyl chloride and not precipitated.

[0044] As one of the more specific embodiments, the preparation method of the carbon nanotube-based polyvinyl chloride conductive masterbatch specifically comprises the following steps:

[0045] S1) The mass fraction of each component of the carbon nanotube prepolymer is:

[0046]

[0047] Each component is weighed, and the carbon nanotubes, plasticizer, lubricant and dispersant are mixed in proportion. After sufficient infiltration, a three-roll mill is used for grinding to prepare a carbon nanotube prepolymer;

[0048] S2) The mass fraction of each component of the polyvinyl chloride conductive masterbatch is:

[0049]

[0050]

[0051] Each material is weighed;

[0052] S3) The carbon nanotube prepolymer, the polyvinyl chloride resin powder, the stabilizer and the impact modifier are mixed uniformly by using a high-speed mixer;

[0053] S4) The mixture is fed into a twin-screw extruder for melt blending extrusion granulation.

[0054] Yet another aspect of the present application provides the use of the carbon nanotube-based PVC conductive masterbatch in the preparation of a PVC product.

[0055] Accordingly, yet another aspect of the present application provides a PVC product prepared from the carbon nanotube-based PVC conductive masterbatch, wherein the content of the carbon nanotube in the PVC product is 1wt% to 5wt%.

[0056] In summary, the carbon nanotube-based PVC conductive masterbatch prepared by the present application has low additive amount, good dispersibility of carbon nanotubes, and excellent performance, and can be widely used in PVC products, and the prepared products have smooth surface, no frost and no oil, and have important commercial value.

[0057] In view of the advantages and technical solutions of the present application, the present application will be further described in conjunction with specific examples, but the present application is not limited in the scope of the described examples. The reagents and raw materials used in the following examples are commercially available, and the test methods not specified in the following examples are usually performed according to conventional conditions or according to the conditions recommended by the manufacturers.

[0058] Example 1

[0059] First step: 500g of modified styrene maleic acid copolymer, 500g of oxidized polyethylene wax are added to 5kg of diisononyl cyclohexane-1,2-dicarboxylate, and stirred and mixed to dissolve the dispersant and lubricant therein. Then 4kg of multi-walled carbon nanotubes are weighed and added to the mixed solution, and left to stand for 8h to allow sufficient infiltration. A three-roll grinder is used to grind and shear the mixture, the spacing of the feeding roll, the middle roll and the discharging roll is set to 20μm, the rotation speed is 200rpm, and the grinding frequency is 5 times, to obtain a 40% carbon nanotube prepolymer.

[0060] Second step: 5kg of 40% carbon nanotube prepolymer, 500g of ACR, 200g of zinc stearate and 4.3kg of PVC powder are weighed and mixed uniformly by using a high-speed mixer for 30min. The parameters of the high-speed mixer are: temperature 80℃, rotation speed 800rpm. The obtained mixture is fed into a twin-screw melt extruder for granulation, and the melt temperature of the twin-screw is set to 170℃, and the screw rotation speed is 300rpm. The extruded melt plastic is cooled by water and dried by air, and then cut into particles to obtain a PVC conductive masterbatch with a carbon nanotube concentration of 20%, which is denoted as 20%CNT-PVC.

[0061] Third step: 20% CNT-PVC conductive masterbatch and PVC granules were added to the high-speed mixer at a mass ratio of 3:20, the temperature was set to 80°C, the speed was set to 800 rpm, and the mixing time was 30 min. The mixed material was transferred to the twin-screw feeder, the melting temperature was set to 170°C, the screw speed was set to 300 rpm, and after extrusion granulation, the product template was prepared according to the relevant standards for testing, and the results are shown in Table 1.

[0062] Example 2

[0063] First step: 200 g of modified styrene maleic acid copolymer, 200 g of oxidized polyethylene wax were added to 6.6 kg of diisononyl cyclohexane-1,2-dicarboxylate, and stirred to disperse the dispersant and lubricant. Then 3 kg of multi-walled carbon nanotubes were added to the mixture and left to soak for 8 hours. A three-roll mill was used for grinding and shearing the mixture, with the inlet roll, middle roll and outlet roll set at a distance of 20 μm and a speed of 200 rpm, and the grinding frequency was 5 times. A 30% carbon nanotube pre-polymer was obtained.

[0064] Second step: 3.33 kg of 30% carbon nanotube pre-polymer, 300 g of ACR, 100 g of zinc stearate and 6.27 kg of PVC powder were mixed evenly in a high-speed mixer for 30 min. The parameters of the high-speed mixer were: temperature 80°C, speed 800 rpm. The obtained mixture was fed into a twin-screw melting extruder for granulation, with the melting temperature set to 170°C and the screw speed set to 300 rpm. The extruded molten plastic was cooled by water and dried by air, and then cut into particles to obtain a 10% carbon nanotube concentration of PVC conductive masterbatch, denoted as 10% CNT-PVC.

[0065] Third step: 10% CNT-PVC conductive masterbatch and PVC granules were added to the high-speed mixer at a mass ratio of 3:7, the temperature was set to 80°C, the speed was set to 800 rpm, and the mixing time was 30 min. The mixed material was transferred to the twin-screw feeder, the melting temperature was set to 170°C, the screw speed was set to 300 rpm, and after extrusion granulation, the product template was prepared according to the relevant standards for testing, and the results are shown in Table 1.

[0066] Example 3

[0067] First step: 100g modified styrene maleic acid copolymer, 100g oxidized polyethylene wax were added into 7.8kg diisononyl cyclohexane-1,2-dicarboxylate, and stirred to mix, so that the dispersant and lubricant were dissolved therein. Then 2kg multi-walled carbon nanotubes were weighed and added into the mixed solution, and left to stand for 8h to fully infiltrate. A three-roll mill was used to grind and shear the mixture, with the distance between the feeding roller, middle roller and discharging roller set to 20μm, the rotation speed set to 200rpm, and the grinding frequency set to 5 times, to obtain a 20% carbon nanotube prepolymer.

[0068] Second step: 3kg 20% carbon nanotube prepolymer, 100g ACR, 100g zinc stearate and 6.8kg PVC powder were mixed uniformly by using a high-speed mixer for 30min. The parameters of the high-speed mixer were: temperature 80℃, rotation speed 800rpm. The obtained mixture was added into a twin-screw melt extruder for granulation, with the melt temperature set to 170℃ and the screw rotation speed set to 300rpm. The extruded melt plastic was cooled by water and dried by air, and then cut into particles to obtain a 6% carbon nanotube concentration polyvinyl chloride conductive masterbatch, denoted as 6%CNT-PVC.

[0069] Third step: 6%CNT-PVC conductive masterbatch and PVC granules were added into a high-speed mixer at a mass ratio of 1:1, with the temperature set to 80℃, the rotation speed set to 800rpm, and the mixing time set to 30min. The mixed material was transferred into a twin-screw feeder, with the melt temperature set to 170℃ and the screw rotation speed set to 300rpm. After extrusion and granulation, the product template was prepared according to the relevant standards for testing, and the results are shown in Table 1.

[0070] Example 4

[0071] The difference between this example and Example 2 is that: in the first step, a three-roll mill was used to grind and shear the mixture, with the distance between the feeding roller, middle roller and discharging roller set to 80μm, the rotation speed set to 200rpm, and the grinding frequency set to 3 times, to obtain a 30% carbon nanotube prepolymer. The remaining steps and formulations were consistent.

[0072] Example 5

[0073] The difference between this example and Example 2 is that: the dispersant modified styrene maleic acid copolymer was replaced by octylphenol polyoxyethylene ether, and the remaining steps and formulations were consistent.

[0074] Example 6

[0075] The difference between this example and Example 2 is that: the lubricant oxidized polyethylene wax was replaced by polyol ester, and the remaining steps and formulations were consistent.

[0076] Example 7

[0077] The difference between this embodiment and embodiment 2 is that the plasticizer cyclohexane-1,2-dicarboxylic acid diisononyl ester is replaced by epoxy soybean oil, and the remaining steps and formulations are consistent.

[0078] Example 8

[0079] The difference between this embodiment and embodiment 2 is that in the second step, 3.33 kg of 30% carbon nanotube prepolymer, 100 g of ACR, 200 g of SBS, 100 g of stabilizer and 6.27 kg of PVC powder are weighed, and stirred with a high-speed mixer for 30 min to mix them uniformly. The remaining steps and formulations are consistent.

[0080] The schematic diagram of the appearance of the carbon nanotube prepolymer prepared in this embodiment is shown in Figure 1 The schematic diagram of the appearance of the polyvinyl chloride conductive master batch prepared is shown in Figure 2 The brittle fracture of the polyvinyl chloride modified product is shown in Figure 3

[0081] Example 9

[0082] The difference between this embodiment and embodiment 2 is that the plasticizer cyclohexane-1,2-dicarboxylic acid diisononyl ester is replaced by diethylene glycol bis-octyl phthalate, the lubricant is replaced by methyl phenyl silicone oil, the dispersant is replaced by dimethyl diallyl ammonium chloride-acrylic acid copolymer, the distance between the feeding roller, the middle roller and the discharging roller is set to 5 μm, the rotating speed is 50 rpm, and the grinding times is 6, and the remaining steps and formulations are consistent.

[0083] Example 10

[0084] The difference between this embodiment and embodiment 2 is that the plasticizer cyclohexane-1,2-dicarboxylic acid diisononyl ester is replaced by acetyl tri-butyl citrate, the lubricant is replaced by calcium stearate, the dispersant is replaced by sodium carboxymethyl cellulose, the distance between the feeding roller, the middle roller and the discharging roller is set to 50 μm, the rotating speed is 300 rpm, and the grinding times is 3, and the remaining steps and formulations are consistent.

[0085] Example 11

[0086] The difference between this embodiment and embodiment 2 is that in the second step, 5 kg of 30% carbon nanotube prepolymer, 450 g of ABS, 50 g of stabilizer and 4.5 kg of PVC powder are weighed, and stirred with a high-speed mixer for 20 min to mix them uniformly. The parameters of the high-speed mixer are that the temperature is 80℃, and the rotating speed is 200 rpm. The obtained mixture is added into a twin-screw melting extruder for granulation, and the melting temperature of the twin-screw is set to 160℃, and the rotating speed of the screw is 600 rpm. The remaining steps and formulations are consistent.

[0087] Example 12

[0088] ​The difference between this example and example 2 is that in the second step, 4 kg of 30% carbon nanotube prepolymer, 600 g of EVA, 100 g of stabilizer and 5.3 kg of PVC powder are weighed and stirred uniformly by a high-speed mixer for 10 min. The parameters of the high-speed mixer are: temperature 50°C, and rotation speed 1000 rpm. The obtained mixture is added into a twin-screw melt extruder by feeding, and the twin-screw melt temperature is set to 200°C, and the screw rotation speed is 50 rpm. The remaining steps and formulations are consistent.

[0089] Comparative Example 1

[0090] The difference between this example and example 8 is that in the first step, 200 g of modified styrene-maleic acid copolymer and 200 g of oxidized polyethylene wax are added to 6.6 kg of diisononyl cyclohexane-1,2-dicarboxylate, and stirred and mixed so that the dispersant and lubricant are dissolved therein. Then, 3 kg of multi-walled carbon nanotubes are weighed and added to the mixed solution, and allowed to stand for 8 h to fully infiltrate, without any treatment, to obtain a 30% mixture. The remaining steps and formulations are consistent with example 8.

[0091] Comparative Example 2

[0092] The difference between this example and example 8 is that in the first step, 200 g of modified styrene-maleic acid copolymer and 200 g of oxidized polyethylene wax are added to 6.6 kg of diisononyl cyclohexane-1,2-dicarboxylate, and stirred and mixed so that the dispersant and lubricant are dissolved therein. Then, 3 kg of multi-walled carbon nanotubes are weighed and added to the mixed solution, and allowed to stand for 8 h to fully infiltrate, without any treatment, to obtain a 30% mixture. The remaining steps and formulations are consistent with example 8.

[0093] Comparative Example 3

[0094] The difference between this example and example 8 is that in the first step, 200 g of modified styrene-maleic acid copolymer and 200 g of oxidized polyethylene wax are added to 6.6 kg of diisononyl cyclohexane-1,2-dicarboxylate, and stirred and mixed so that the dispersant and lubricant are dissolved therein. Then, 3 kg of multi-walled carbon nanotubes are weighed and added to the mixed solution, and allowed to stand for 8 h to fully infiltrate, without any treatment, to obtain a 30% mixture. The remaining steps and formulations are consistent with example 8.

[0095] The brittle fracture surface of the polyvinyl chloride modified product obtained in this comparative example is shown in FIG. 1. Figure 4

[0096] Comparative Example 4

[0097] The difference between this example and example 8 is that in the first step, 200 g of oxidized polyethylene wax is added to 6.8 kg of diisononyl cyclohexane-1,2-dicarboxylate, and stirred and mixed so that the lubricant is dissolved therein. The remaining steps and formulations are consistent with example 8.​

[0098] Comparative Example 5

[0099] The difference between this example and Example 8 is in the second step: 3.33 kg of 30% carbon nanotube prepolymer, 100 g of stabilizer and 6.57 kg of PVC powder are weighed and stirred uniformly by using a high-speed mixer for 30 min. The remaining steps and the formulation are consistent with Example 8.

[0100] The performance characterization results of the polyvinyl chloride products obtained in Examples 1-8 and Comparative Examples 1-5 are shown in Table 1.

[0101] Table 1 Performance characterization of polyvinyl chloride modified products

[0102]

[0103] As can be seen from Table 1, in the preparation of the conductive master batch, the dusting condition is relatively serious when the carbon nanotubes are directly added without plasticizer infiltration treatment in Comparative Example 1, and the dusting phenomenon also occurs in Comparative Example 2 without ball milling and three-roll milling treatment, because part of the carbon nanotubes cannot be infiltrated, and the combination of the carbon nanotubes and the plasticizer is relatively loose, so the processes of the two are not conducive to the implementation of production. However, there is no dusting condition when the carbon nanotubes are prepared into a conductive master batch after being infiltrated by a plasticizer and milled by a ball mill or a three-roll mill. The resistance of the modified polyvinyl chloride product in Comparative Example 3 is only 3.2*10 7 , which is 4 orders of magnitude higher than that of Example 8 using three-roll milling, because the ball milling can only impact and crush the carbon nanotubes to shorten the length of the carbon nanotubes, and the dispersion effect of the carbon nanotube bundles is poor. The three-roll milling fully extrudes the plasticizer, lubricant, dispersant and carbon nanotubes by the pressure of the rollers, shears and disperses the carbon nanotubes, and at the same time, the dispersant wraps the dispersed carbon nanotubes by the force to avoid the aggregation of the carbon nanotubes, so the conductive performance is better. In Comparative Example 4, no dispersant is added, so the resistance 4.6*10 6 is 3 orders of magnitude higher than that of Example 8. In Comparative Example 5, no impact modifier ACR and SBS are added, and both of them can appropriately increase the processing torque and improve the shearing force in the preparation process of the polyvinyl chloride conductive master batch, and the benzene ring conjugated structure contained in SBS can produce a force with the carbon tube, which all helps to disperse the carbon nanotubes.

[0104] As can be seen from Table 1, the carbon nanotubes in the conductive master batch modified polyvinyl chloride product prepared by the present application are uniformly dispersed without obvious aggregation, while Figure 3 the carbon nanotubes in the conductive master batch modified polyvinyl chloride product of Comparative Example 3 are in an aggregated state and are obviously not uniformly dispersed. Figure 4

[0105] ​The above describes in detail the carbon nanotube-based polyvinyl chloride conductive master batch and the preparation method thereof provided by the embodiments of the present application. The above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation and application range can be changed, and the above description should not be understood as a limitation on the present application.

[0106] It should also be noted that the terms "comprising", "containing" or any other variant thereof are intended to cover a non-exclusive inclusion, so that a product or system that includes a list of elements not only includes those elements, but also includes other elements not explicitly listed, or inherent to such product or system. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the product or system that includes the element.

[0107] It should be understood that the term "and / or" used herein is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0108] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the forms disclosed herein, should not be considered as excluding other embodiments, and can be used in various other combinations, modifications and environments, and can be modified by the above teachings or related art or knowledge within the scope of the application conceived herein. The changes and modifications made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the claims of the present application.

Claims

1. A carbon nanotube-based polyvinyl chloride conductive master batch, characterized by, The raw materials for preparing the polyvinyl chloride conductive masterbatch include the following components in parts by mass: carbon nanotube premix 30-50%, polyvinyl chloride resin 40-80%, impact modifier 1-5%, and stabilizer 0.5-2%, wherein the carbon nanotube premix is prepared from the following components in parts by mass: carbon nanotube 20-40%, plasticizer 50-80%, lubricant 1-5%, and dispersant 0.2-5%, and the carbon nanotube premix is prepared by fully immersing the carbon nanotube in a mixed solution containing the plasticizer, lubricant, and dispersant, and then grinding with a three-roll grinder; the plasticizer is at least any one selected from diethylene glycol bis-octyl phthalate, epoxy soybean oil, acetyl tri-butyl citrate, and diisononyl cyclohexane-1,2-dicarboxylate; the lubricant is at least any one selected from oxidized polyethylene wax, calcium stearate, polyol ester, and methyl phenyl silicone oil; and the dispersant is at least any one selected from dimethyl diallyl ammonium chloride-acrylic acid copolymer, octylphenol polyoxyethylene ether, sodium carboxymethyl cellulose, and modified styrene maleic acid copolymer.

2. The carbon nanotube-based polyvinyl chloride conductive master batch according to claim 1, characterized by: The impact modifier is at least any one selected from methyl methacrylate-acrylate copolymer, methyl methacrylate-butadiene-styrene terpolymer, styrene-butadiene triblock copolymer, and ethylene-vinyl acetate copolymer.

3. The carbon nanotube based polyvinyl chloride conductive masterbatch as claimed in claim 1, wherein: The stabilizer is at least any one selected from zinc stearate, calcium stearate, rare earth stearate, triphenyl phosphite, and di-n-octyl tin isooctyl dimercaptacetate.

4. The method for preparing a carbon nanotube-based polyvinyl chloride conductive master batch according to any one of claims 1 to 3, wherein It comprises: immersing the carbon nanotube in a mixed solution containing the plasticizer, lubricant, and dispersant, and then grinding with a three-roll grinder to prepare the carbon nanotube premix; mixing the carbon nanotube premix, polyvinyl chloride resin, stabilizer, and impact modifier uniformly, and then melt blending extrusion granulation of the obtained mixture to prepare the carbon nanotube-based polyvinyl chloride conductive masterbatch.

5. The method of claim 4, wherein: The grinding comprises: sequentially passing through the horizontal feeding roller, middle roller, and discharging roller; wherein the spacing between the feeding roller, middle roller, and discharging roller is 5-80 μm, the roller rotation speed is 50-300 rpm, and the grinding passes are 3-6.

6. The production method according to claim 4, characterized by, It comprises: mixing the carbon nanotube premix, polyvinyl chloride resin, stabilizer, and impact modifier uniformly with a high-speed mixer; the rotation speed of the high-speed mixer is 200-1000 rpm, the mixing temperature is 50-80 °C, and the mixing time is 10-30 min.

7. The production method according to claim 4, characterized by, It comprises: inputting the mixture into a twin-screw extrusion granulator for melt blending extrusion granulation; the temperature of the twin-screw extrusion granulator is 160-200 °C, and the screw rotation speed is 50-600 rpm.

8. Use of the carbon nanotube-based polyvinyl chloride conductive masterbatch of any one of claims 1-3 in preparing a polyvinyl chloride product.

9. A polyvinyl chloride article, characterized by, It is prepared from the carbon nanotube-based polyvinyl chloride conductive masterbatch of any one of claims 1-3, and the carbon nanotube content in the polyvinyl chloride product is 1-5 wt%.

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