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

Abstract

The invention discloses a carbon nanotube-based polyvinyl chloride conductive master batch as well as a preparation method and application thereof. Preparation raw materials of the polyvinyl chloride conductive master batch comprise the following components: a carbon nanotube prepolymer, polyvinyl chloride resin, an impact modifier and a stabilizer, and the carbon nanotube prepolymer is prepared from a carbon nanotube, a plasticizer, a lubricant and a dispersant. The preparation process of the polyvinyl chloride conductive master batch based on the carbon nanotubes is easy to operate and environmentally friendly, and the carbon nanotubes are pretreated by adding the plasticizer and the dispersing agent, so that the carbon nanotubes are more easily dispersed in polyvinyl chloride and are not separated out. Moreover, the conductive master batch is low in addition amount and excellent in performance, can be widely applied to polyvinyl chloride products, and has important commercial value.

Description

Technical Field

[0001] The invention relates to a polyvinyl chloride conductive masterbatch, in particular to a polyvinyl chloride conductive masterbatch based on carbon nanotubes and a preparation method and application thereof, belonging to the technical field of conductive plastics. Background Art

[0002] Polyvinyl chloride is a widely used plastic resin, widely used in various fields such as medicine, chemical industry, machinery manufacturing, aerospace, etc. Insulation is a common feature of PVC as a plastic. In certain specific application scenarios, such as conveying devices in coal mines, storage tanks in chemical plants, and exhaust ventilation ducts, insulation will be a dangerous factor in safety accidents. Therefore, PVC needs to be anti-statically modified so that the charge can be transferred in time under specific circumstances. Carbon nanotubes are a filler with excellent electrical / thermal conductivity and strong stability. With a very small addition amount, polyvinyl chloride products can have a certain charge transfer ability without affecting the mechanical properties of the body. However, since carbon nanotubes are easy to fly in the air during use, causing harm to the health of operators, and are not easy to disperse in high-viscosity polyvinyl chloride melts, their production and application are difficult.

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

[0004] CN110564113A sets a strong magnetic field outside a sealed container, and after mixing and stirring graphene, carbon nanotubes, metal powders, metal oxide powders, conductive carbon black and base materials by the action of magnetic force, granulation is performed using a single screw extruder. Magnetic field and mechanical stirring are essentially shear mixing by external force, and cannot achieve a good dispersion effect. Moreover, during the operation, graphene, carbon nanotubes, conductive carbon black and other powders that are easy to fly are not processed, which is detrimental to the health of production operators. Summary of the invention

[0005] The main purpose of the present invention is to provide a polyvinyl chloride conductive masterbatch based on carbon nanotubes and a preparation method thereof, so as to solve any of the above and other potential problems of the prior art.

[0006] Another object of the present invention is to provide an application of the carbon nanotube-based polyvinyl chloride conductive masterbatch.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0008] The embodiment of the present invention provides a polyvinyl chloride conductive masterbatch based on carbon nanotubes. The raw materials for preparing the polyvinyl chloride conductive masterbatch include 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.

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

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

[0011] The embodiment of the present invention further provides a method for preparing the aforementioned carbon nanotube-based polyvinyl chloride conductive masterbatch, which comprises:

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

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

[0014] The embodiment of the present invention also provides the use of the carbon nanotube-based polyvinyl chloride conductive masterbatch in the preparation of polyvinyl chloride products.

[0015] Correspondingly, an embodiment of the present invention further provides a polyvinyl chloride product, which is made from the aforementioned carbon nanotube-based polyvinyl chloride conductive masterbatch, and the carbon nanotube content in the polyvinyl chloride product is 1wt% to 5wt%.

[0016] Compared with the prior art, the beneficial effects of the present invention include:

[0017] 1) The present invention mixes a plasticizer, a dispersant, a lubricant and carbon nanotubes and grinds them to preliminarily disperse the carbon nanotubes, and combines the dispersant and the carbon nanotubes together, which is more conducive to uniform dispersion of the carbon nanotubes in the polyvinyl chloride resin; at the same time, a plasticizer with good compatibility with the carbon nanotubes is used as a carrier between the polyvinyl chloride resin and the carbon nanotubes to avoid precipitation and uneven dispersion caused by poor compatibility between the carbon nanotubes and the polyvinyl chloride resin; the use of plasticizer for impregnation can also avoid the problem of easy flying of powder during the use of the carbon nanotubes, and the plasticizer is not volatile, low in toxicity, and has good stability, and the preparation process is green, 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 dispersibility. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

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

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

[0022] Figure 3 is a brittle cross-section diagram of the polyvinyl chloride modified 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 view of the problems existing in the above-mentioned prior art, the inventors of the present invention have conducted extensive and in-depth research and provided a polyvinyl chloride conductive masterbatch based on carbon nanotubes and a preparation method thereof, wherein the components of the conductive masterbatch include: carbon nanotubes, a plasticizer, a dispersant, a lubricant, polyvinyl chloride resin powder, an impact modifier, and a stabilizer. The technical solution, its implementation process and principle are further explained as follows.

[0025] As one aspect of the technical solution of the present invention, the raw materials for preparing a carbon nanotube-based polyvinyl chloride conductive masterbatch include 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 calculated by weight: 20% to 40% carbon nanotubes, 50% to 80% plasticizer, 1% to 5% lubricant and 0.2% to 5% dispersant.

[0027] In some embodiments, the plasticizer may include at least any one of diethylene glycol dioctyl phthalate, epoxy soybean oil, acetyl tributyl citrate, and cyclohexane-1,2-diisononyl dicarboxylate, but is not limited thereto. The plasticizer used in the present invention is directly used as a dispersion carrier to improve the dispersion effect of the carbon nanotubes without causing pollution to the environment, and is also beneficial to the processability of the masterbatch. Further, the plasticizer is an environmentally friendly plasticizer, and can improve the compatibility between the carbon nanotubes and the polyvinyl chloride resin, which helps the dispersion effect of the carbon nanotubes in the polyvinyl chloride resin.

[0028] In some embodiments, the lubricant may include at least any one of oxidized polyethylene wax, calcium stearate, polyol ester, and methylphenyl silicone oil, but is not limited thereto.

[0029] In some embodiments, the dispersant may include at least any one of dimethyldiallylammonium chloride-acrylic acid copolymer, octylphenol polyoxyethylene ether, sodium carboxymethylcellulose, modified styrene maleic acid copolymer, etc., but is not limited thereto.

[0030] In some embodiments, the raw materials for preparing the polyvinyl chloride conductive masterbatch include the following components calculated by mass: 30% to 50% carbon nanotube prepolymer, 40% to 80% polyvinyl chloride resin, 1% to 5% impact modifier and 0.5% to 2% stabilizer.

[0031] In some embodiments, the impact modifier may include at least any one of methyl methacrylate-acrylate copolymer (ACR), methyl methacrylate-butadiene-styrene terpolymer (ABS), styrene-butadiene triblock copolymer (SBS), and ethylene-vinyl acetate copolymer (EVA), but is not limited thereto. The addition of the impact modifier in the present invention is helpful for the processing performance and mechanical properties of the masterbatch. In addition, improper selection of the impact modifier will have a negative impact on the dispersion of the carbon nanotubes. The impact modifier selected by the present invention has almost no negative impact on the dispersion of the carbon nanotubes, and can even have a positive impact.

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

[0033] As another aspect of the technical solution of the present invention, a method for preparing a polyvinyl chloride conductive masterbatch based on carbon nanotubes comprises:

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

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

[0036] In some embodiments, the preparation process of the carbon nanotube prepolymer includes: mixing carbon nanotubes, plasticizers, lubricants and dispersants uniformly, grinding with a three-roll mill, and preparing the carbon nanotube prepolymer. The present invention mixes the plasticizer, dispersant, lubricant and carbon nanotubes and processes them with a three-roll mill to preliminarily disperse the carbon nanotubes, and combines the dispersant and the carbon nanotubes together, which is more conducive to the uniform dispersion of the carbon nanotubes in the polyvinyl chloride resin. At the same time, a plasticizer with good compatibility with the carbon nanotubes is used as a carrier between the polyvinyl chloride resin and the carbon nanotubes to avoid the problems of precipitation and uneven dispersion caused by the poor compatibility of the carbon nanotubes and the polyvinyl chloride resin.

[0037] Furthermore, the present invention uses plasticizer to soak in advance, and pre-disperses the carbon nanotubes in a three-roll mill, which also avoids the problem of powder flying during the use of the carbon nanotubes. In addition, the plasticizer used is not easy to volatilize, has low toxicity, and has good stability. The preparation process is green, environmentally friendly, simple and feasible.

[0038] Furthermore, the pretreatment method three-roll grinding used in the present invention is a new method in the field of masterbatch preparation. Different from ball milling or high-speed stirring, three-roll grinding can effectively combine plasticizers, lubricants, dispersants, etc. with carbon nanotubes, thereby improving the dispersion effect of carbon nanotubes in polyvinyl chloride resin.

[0039] In some more specific embodiments, the grinding includes: grinding in sequence through a horizontal feed roller, a middle roller, and a discharge roller; the specific process is to achieve the grinding and dispersion effect by mutual extrusion of the surfaces of the horizontal feed roller, the middle roller, and the discharge roller and friction at different speeds, wherein the spacing between the feed roller, the middle roller, and the discharge roller is 5 to 80 μm, the roller speed is 50 to 300 rpm, and the number of grinding times is 3N6 times.

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

[0041] Specifically, 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.

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

[0043] In some more specific embodiments, the preparation method of the polyvinyl chloride conductive masterbatch based on carbon nanotubes specifically includes: after mixing plasticizer, dispersant and lubricant uniformly, adding carbon nanotubes, preliminarily dispersing with a three-roller machine after sufficient impregnation, preparing carbon nanotube prepolymer; using a high-speed mixer to mix the prepolymer and polyvinyl chloride resin powder, impact modifier and stabilizer uniformly, and extruding the obtained mixture with a twin-screw extruder for granulation. The preparation process is simple to operate, green and environmentally friendly, and the addition of plasticizer and dispersant to pretreat carbon nanotubes makes it easier to disperse in polyvinyl chloride and does not precipitate.

[0044] Among them, as one of the more specific embodiments, the preparation method of the polyvinyl chloride conductive masterbatch based on carbon nanotubes specifically includes the following steps:

[0045] S1) The mass fractions of each component of the carbon nanotube prepolymer are:

[0046]

[0047] Weigh each component, mix the carbon nanotubes, plasticizer, lubricant and dispersant in proportion. After sufficient impregnation, grind with a three-roll mill to prepare a carbon nanotube prepolymer;

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

[0049]

[0050]

[0051] Weigh each material;

[0052] S3) mixing the carbon nanotube prepolymer, the polyvinyl chloride resin powder, the stabilizer and the impact modifier uniformly with a high-speed mixer;

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

[0054] Another aspect of the embodiments of the present invention further provides the use of the carbon nanotube-based polyvinyl chloride conductive masterbatch in the preparation of polyvinyl chloride products.

[0055] Correspondingly, another aspect of the embodiments of the present invention further provides a polyvinyl chloride product, which is made from the aforementioned carbon nanotube-based polyvinyl chloride conductive masterbatch, and the carbon nanotube content in the polyvinyl chloride product is 1wt% to 5wt%.

[0056] In summary, the carbon nanotube-based polyvinyl chloride conductive masterbatch prepared by the present invention has a low addition amount, good carbon nanotube dispersibility, and excellent performance, and can be widely used in polyvinyl chloride products. The prepared products have a smooth surface, no frosting, and no oil, and have important commercial value.

[0057] The advantages and technical solutions of the present invention are further described below in conjunction with specific examples, but the present invention is not limited to the scope of the examples. The reagents and raw materials used in the following examples are commercially available, and the test methods without specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturers.

[0058] Example 1

[0059] Step 1: Add 500g of modified styrene maleic acid copolymer and 500g of oxidized polyethylene wax to 5kg of cyclohexane-1,2-diisononyl dicarboxylate, stir and mix, so that the dispersant and lubricant are dissolved therein. Then weigh 4kg of multi-walled carbon nanotubes and add them to the mixed solution, let it stand for 8h to make it fully infiltrated. Use a three-roll mill to grind and shear the mixture, set the spacing between the feed roller, the middle roller, and the discharge roller to 20μμm, the rotation speed to 200rpm, and the grinding number to 5 times to obtain 40% carbon nanotube prepolymer.

[0060] Step 2: Weigh 5kg 40% carbon nanotube prepolymer, 500g ACR, 200g zinc stearate and 4.3kg PVC powder, and mix them evenly by stirring in a high-speed mixer for 30 minutes. The parameters of the high-speed mixer are: temperature is 80°C, speed is 800rpm. The obtained mixture is fed into a twin-screw melt extrusion granulation, the twin-screw melt temperature is set to 170°C, and the screw speed is 300rpm. The extruded molten plastic is water-cooled and air-dried to obtain a polyvinyl chloride conductive masterbatch with a carbon nanotube concentration of 20%, recorded as 20% CNT-PVC.

[0061] Step 3: Add 20% CNT-PVC conductive masterbatch and PVC granules in a mass ratio of 3:20 into a high-speed mixer, set the temperature to 80°C, the speed to 800rpm, and the mixing time to 30min. The mixed materials are transferred to the twin-screw feeding, the melt temperature is set to 170°C, the screw speed is set to 300rpm, and after extrusion granulation, the product template is made according to the relevant standards for testing. The results are shown in Table 1.

[0062] Example 2

[0063] Step 1: Add 200g of modified styrene maleic acid copolymer and 200g of oxidized polyethylene wax to 6.6kg of cyclohexane-1,2-diisononyl dicarboxylate, stir and mix, so that the dispersant and lubricant are dissolved therein. Then weigh 3kg of multi-walled carbon nanotubes and add them to the mixed solution, let it stand for 8h to make it fully infiltrated. Use a three-roll mill to grind and shear the mixture, set the spacing between the feed roller, the middle roller, and the discharge roller to 20μm, the rotation speed to 200rpm, and the grinding number to 5 times to obtain 30% carbon nanotube prepolymer.

[0064] Step 2: Weigh 3.33kg 30% carbon nanotube prepolymer, 300g ACR, 100g zinc stearate and 6.27kg PVC powder, and mix them evenly by stirring in a high-speed mixer for 30 minutes. The parameters of the high-speed mixer are: temperature is 80°C, speed is 800rpm. The obtained mixture is fed into a twin-screw melt extrusion granulation, the twin-screw melt temperature is set to 170°C, and the screw speed is 300rpm. The extruded molten plastic is water-cooled and air-dried to obtain a polyvinyl chloride conductive masterbatch with a carbon nanotube concentration of 10%, recorded as 10% CNT-PVC.

[0065] Step 3: Add 10% CNT-PVC conductive masterbatch and PVC granules in a mass ratio of 3:7 to a high-speed mixer, set the temperature to 80°C, the speed to 800rpm, and the mixing time to 30min. The mixed materials are transferred to the twin-screw feeding, the melt temperature is set to 170°C, the screw speed is set to 300rpm, and after extrusion granulation, the product template is made according to the relevant standards for testing. The results are shown in Table 1.

[0066] Example 3

[0067] Step 1: Add 100g of modified styrene maleic acid copolymer and 100g of oxidized polyethylene wax to 7.8kg of cyclohexane-1,2-diisononyl dicarboxylate, stir and mix, so that the dispersant and lubricant are dissolved therein. Then weigh 2kg of multi-walled carbon nanotubes and add them to the mixed solution, let it stand for 8h to make it fully infiltrated. Use a three-roll mill to grind and shear the mixture, set the spacing between the feed roller, the middle roller, and the discharge roller to 20μm, the rotation speed to 200rpm, and the grinding number to 5 times to obtain 20% carbon nanotube prepolymer.

[0068] Step 2: Weigh 3kg 20% ​​carbon nanotube prepolymer, 100g ACR, 100g zinc stearate and 6.8kg PVC powder, and mix them evenly by stirring in a high-speed mixer for 30 minutes. The parameters of the high-speed mixer are: temperature is 80°C, speed is 800rpm. The obtained mixture is fed into a twin-screw melt extrusion granulation, the twin-screw melt temperature is set to 170°C, and the screw speed is 300rpm. The extruded molten plastic is water-cooled and air-dried to obtain a polyvinyl chloride conductive masterbatch with a carbon nanotube concentration of 6%, recorded as 6% CNT-PVC.

[0069] Step 3: Add 6% CNT-PVC conductive masterbatch and PVC granules in a mass ratio of 1:1 into a high-speed mixer, set the temperature to 80°C, the speed to 800rpm, and the mixing time to 30min. The mixed materials are transferred to the twin-screw feeding, the melt temperature is set to 170°C, the screw speed is set to 300rpm, and after extrusion granulation, the product template is made according to the relevant standards for testing. The results are shown in Table 1.

[0070] Example 4

[0071] The difference between this embodiment and embodiment 2 is that: the first step is to grind and shear the mixture using a three-roll grinder, set the spacing between the feed roller, the middle roller, and the discharge roller to 80 μm, the rotation speed to 200 rpm, and the grinding times to 3 times to obtain a 30% carbon nanotube prepolymer. The remaining steps are consistent with the formula.

[0072] Example 5

[0073] The difference between this embodiment and embodiment 2 is that the dispersant-modified styrene maleic acid copolymer is replaced by octylphenol polyoxyethylene ether, and the remaining steps and formulas are the same.

[0074] Example 6

[0075] The difference between this embodiment and embodiment 2 is that the lubricant oxidized polyethylene wax is replaced by polyol ester, and the remaining steps and formulas are the same.

[0076] Example 7

[0077] The difference between this embodiment and embodiment 2 is that the plasticizer diisononyl cyclohexane-1,2-dicarboxylate is replaced with epoxidized soybean oil, and the remaining steps and formulas are the same.

[0078] Example 8

[0079] The difference between this embodiment and embodiment 2 is that: Step 2: weigh 3.33 kg 30% carbon nanotube prepolymer, 100 g ACR, 200 g SBS, 100 g stabilizer and 6.27 kg PVC powder, and stir them for 30 minutes using a high-speed mixer to mix them evenly. The remaining steps are consistent with the formula.

[0080] The schematic diagram of the appearance of the carbon nanotube prepolymer prepared in this example is as follows Figure 1 The appearance diagram of the prepared polyvinyl chloride conductive masterbatch is shown in Figure 2 As shown in the figure, the brittle section diagram of the modified polyvinyl chloride product is as follows Figure 3 shown.

[0081] Example 9

[0082] The difference between this embodiment and embodiment 2 is that the plasticizer diisononyl cyclohexane-1,2-dicarboxylate is replaced by diethylene glycol dioctyl phthalate, the lubricant is replaced by methylphenyl silicone oil, the dispersant is replaced by dimethyldiallylammonium chloride-acrylic acid copolymer, the spacing between the feed roller, the middle roller, and the discharge roller is set to 5 μm, the rotation speed is 50 rpm, the grinding number is 6 times, and the remaining steps are consistent with the formula.

[0083] Example 10

[0084] The difference between this embodiment and embodiment 2 is that the plasticizer diisononyl cyclohexane-1,2-dicarboxylate is replaced by tributyl acetyl citrate, the lubricant is replaced by calcium stearate, the dispersant is replaced by sodium carboxymethyl cellulose, the spacing between the feed roller, the middle roller, and the discharge roller is set to 50 μm, the rotation speed is 300 rpm, the grinding number is 3 times, and the remaining steps are consistent with the formula.

[0085] Embodiment 11

[0086] The difference between this embodiment and embodiment 2 is: Step 2: weigh 5kg 30% carbon nanotube prepolymer, 450g ABS, 50g stabilizer and 4.5kg PVC powder, and mix them evenly by stirring for 20min using a high-speed mixer. The parameters of the high-speed mixer are: temperature of 80°C and speed of 200rpm. The obtained mixture is fed into a twin-screw melt extrusion granulation, the twin-screw melt temperature is set to 160°C, and the screw speed is 600rpm. The remaining steps are consistent with the formula.

[0087] Example 12

[0088] The difference between this embodiment and embodiment 2 is: Step 2: Weigh 4kg 30% carbon nanotube prepolymer, 600g EVA, 100g stabilizer and 5.3kg PVC powder, and mix them evenly by stirring for 10min using a high-speed mixer. The parameters of the high-speed mixer are: temperature of 50°C and speed of 1000rpm. The obtained mixture is fed into a twin-screw melt extrusion granulation, the twin-screw melt temperature is set to 200°C, and the screw speed is 50rpm. The remaining steps are consistent with the formula.

[0089] Comparative Example 1

[0090] The difference between this embodiment and embodiment 8 is that 1 kg of carbon nanotubes, 66 g of modified styrene maleic acid copolymer, 66 g of oxidized polyethylene wax, 300 g of ACR, 100 g of zinc stearate and 8.648 kg of PVC powder are directly weighed and mixed evenly by a high-speed mixer for 30 min. The parameters of the high-speed mixer are: temperature of 80° C., speed of 800 rpm. The remaining steps and formula are consistent with those of embodiment 8.

[0091] Comparative Example 2

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

[0093] Comparative Example 3

[0094] The difference between this embodiment and embodiment 8 is that in the first step, 200g of modified styrene maleic acid copolymer and 200g of oxidized polyethylene wax are added to 6.6kg of cyclohexane-1,2-diisononyl dicarboxylate, and stirred to dissolve the dispersant and lubricant therein. Then, 3kg of multi-walled carbon nanotubes are weighed and added to the mixed solution, and the mixture is allowed to stand for 8h to allow it to be fully infiltrated, and then ground with a planetary ball mill at 500r / min for 4h to obtain a 30% mixture. The remaining steps and formula are consistent with those of embodiment 8.

[0095] The brittle cross-section diagram of the polyvinyl chloride modified product obtained in this comparative example is as follows: Figure 4 shown.

[0096] Comparative Example 4

[0097] The difference between this embodiment and embodiment 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 the mixture is stirred to dissolve the lubricant therein. The remaining steps and formula are the same as those in embodiment 8.

[0098] Comparative Example 5

[0099] The difference between this embodiment and embodiment 8 is that 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 mixed evenly by a high-speed mixer for 30 minutes. The remaining steps and formula are the same as those in embodiment 8.

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

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

[0102]

[0103] As can be seen from Table 1, in the process of preparing the conductive masterbatch, the dust emission is quite serious when the carbon nanotubes are directly added without plasticizer impregnation treatment in Comparative Example 1. Secondly, dust emission also occurs in Comparative Example 2 without ball milling and three-roll grinding treatment. The reason is that some carbon nanotubes fail to be impregnated, and the carbon nanotubes are not tightly combined with the plasticizer. Therefore, both processes are not conducive to production. However, there is no dust emission when the carbon nanotubes are prepared into conductive masterbatch after plasticizer impregnation and ball milling or three-roll grinding. 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 ball milling can only impact and crush carbon nanotubes to shorten the length of carbon nanotubes, and the effect of dispersing carbon nanotube bundles is poor. Three-roll milling fully squeezes the plasticizer, lubricant, dispersant and carbon nanotubes through the pressure of the rollers, and while shearing and dispersing the carbon nanotubes, the dispersant wraps the dispersed carbon nanotubes through the force to prevent the carbon nanotubes from agglomerating, so the conductive performance is better. No dispersant was added in Comparative Example 4, so the resistance is 4.6*10 6 It is 3 orders of magnitude higher than that of Example 8. In Comparative Example 5, no impact modifier ACR and SBS were added. Both of them can appropriately increase the processing torque and the shear force in the preparation process of polyvinyl chloride conductive masterbatch, and the conjugated structure of the benzene ring contained in SBS can generate force with carbon nanotubes, which is conducive to the dispersion of carbon nanotubes.

[0104] from Figure 3 It can be seen that the carbon nanotubes in the conductive masterbatch modified polyvinyl chloride product prepared by the present invention are evenly dispersed without obvious agglomeration. Figure 4 This is the conductive masterbatch modified polyvinyl chloride product of Comparative Example 3, in which the carbon nanotubes are in an aggregated state and are obviously unevenly dispersed.

[0105] The above is a detailed introduction to a polyvinyl chloride conductive masterbatch based on carbon nanotubes and a preparation method thereof provided in the embodiments of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application; at the same time, for a person skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present application.

[0106] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such a product or system. In the absence of more restrictions, the elements defined by the sentence "including a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0107] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "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 form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the application concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not deviate from the spirit and scope of the present application, and should be within the scope of protection of the claims attached to the present application.

Claims

1. A polyvinyl chloride conductive masterbatch based on carbon nanotubes, characterized in that: The raw materials for preparing the polyvinyl chloride conductive masterbatch include 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.

2. The carbon nanotube-based polyvinyl chloride conductive masterbatch according to claim 1, characterized in that: The carbon nanotube prepolymer is prepared from the following components calculated by mass: 20% to 40% of carbon nanotubes, 50% to 80% of plasticizer, 1% to 5% of lubricant and 0.2% to 5% of dispersant.

3. The carbon nanotube-based polyvinyl chloride conductive masterbatch according to claim 1, characterized in that: The plasticizer includes at least any one of diethylene glycol dioctyl phthalate, epoxy soybean oil, acetyl tributyl citrate, and cyclohexane-1,2-diisononyl dicarboxylate; And / or, the lubricant includes at least any one of oxidized polyethylene wax, calcium stearate, polyol ester, and methylphenyl silicone oil; And / or, the dispersant includes at least any one of dimethyldiallylammonium chloride-acrylic acid copolymer, octylphenol polyoxyethylene ether, sodium carboxymethyl cellulose, and modified styrene maleic acid copolymer.

4. The polyvinyl chloride conductive masterbatch based on carbon nanotubes according to claim 1, characterized in that: The raw materials for preparing the polyvinyl chloride conductive masterbatch include the following components calculated by mass: 30% to 50% of carbon nanotube prepolymer, 40% to 80% of polyvinyl chloride resin, 1% to 5% of impact modifier and 0.5% to 2% of stabilizer; And / or, the impact modifier includes at least any one of methyl methacrylate-acrylate copolymer, methyl methacrylate-butadiene-styrene terpolymer, styrene-butadiene triblock copolymer, and ethylene-vinyl acetate copolymer; And / or, the stabilizer includes at least any one of zinc stearate, calcium stearate, rare earth stearate, triphenyl phosphite, and di-n-octyltin dithioglycolate.

5. The method for preparing the polyvinyl chloride conductive masterbatch based on carbon nanotubes according to any one of claims 1 to 4, characterized in that: include: The carbon nanotubes, plasticizer, lubricant and dispersant are uniformly mixed and ground to prepare a carbon nanotube prepolymer; The carbon nanotube prepolymer, polyvinyl chloride resin, stabilizer and impact modifier are uniformly mixed, and then the obtained mixture is subjected to melt blending, extrusion and granulation to prepare carbon nanotube-based polyvinyl chloride conductive masterbatch.

6. The preparation method according to claim 5, characterized in that: include: The carbon nanotubes, plasticizer, lubricant and dispersant are uniformly mixed and ground with a three-roll mill to prepare a carbon nanotube prepolymer; Preferably, the grinding includes: grinding in sequence through a horizontal feed roller, a middle roller, and a discharge roller; wherein the spacing between the feed roller, the middle roller, and the discharge roller is 5 to 80 μm, the roller speed is 50 to 300 rpm, and the number of grinding times is 3 to 6 times.

7. The preparation method according to claim 5, characterized in that: include: A high-speed mixer is used to evenly mix the carbon nanotube prepolymer, polyvinyl chloride resin, stabilizer and impact modifier; preferably, 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.

8. The preparation method according to claim 5, characterized in that: include: The mixture is input into a twin-screw extruder granulator for melt blending and extrusion granulation; preferably, the temperature of the twin-screw extruder granulator is 160-200° C., and the screw speed is 50-600 rpm.

9. Use of the carbon nanotube-based polyvinyl chloride conductive masterbatch according to any one of claims 1 to 4 in the preparation of polyvinyl chloride products.

10. A polyvinyl chloride product, characterized in that: It is made from the carbon nanotube-based polyvinyl chloride conductive masterbatch as described in any one of claims 1 to 4, and the carbon nanotube content in the polyvinyl chloride product is 1wt% to 5wt%.

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