A core-shell structured rare earth-based wide-temperature conductive powder, its preparation method and application

Abstract

This invention provides a core-shell structured rare-earth-based wide-temperature conductive powder, its preparation method, and its applications. The powder comprises a high-temperature conductive core and a room-temperature conductive shell. The core is doped cerium oxide with a particle size controlled between 1-3 μm and a whiteness ≥80%. The rare-earth-based wide-temperature conductive powder of this invention, through a rare-earth-based white substrate combined with a thin composite conductive shell design, retains the material's high whiteness and excellent color compatibility, overcoming the shortcomings of traditional carbon-based and metal conductive fillers in terms of dull color. It also achieves stable antistatic effects under both room and high-temperature environments, with a wide range of applicable temperatures. While ensuring the aesthetic appearance and color diversity of the finished product, it significantly improves the antistatic level and safety of PVC packaging. The preparation process is simple and controllable, suitable for industrial mass production, and has high application and promotion value.

Description

Technical Field

[0001] This invention belongs to the field of conductive materials, and in particular relates to a core-shell structured rare earth-based wide-temperature conductive powder, its preparation method, and its application. Background Technology

[0002] Currently, commercially available conductive materials generally face the dual bottleneck of balancing dark color with wide-temperature conductivity, hindering their application in optics, high-temperature electronics, and flexible electronics. Mainstream conductive systems are primarily carbon-based, metal-based, and oxide-based. Carbon materials are naturally black due to strong visible light absorption, and it's difficult to achieve lighter colors with metal fillers and dark conductive oxides. Reducing filler content to improve color leads to discontinuous conductive networks and a sharp increase in resistivity. Since color and conductivity are significantly negatively correlated, this fails to meet the requirements for transparent and light-colored applications.

[0003] Regarding temperature adaptability, existing materials struggle to simultaneously achieve high conductivity at room temperature and stable conductivity at high temperatures. Metals and alloys exhibit excellent conductivity at room temperature, but their resistivity increases significantly with rising temperature, making them prone to oxidation, migration, and structural failure at high temperatures. Summary of the Invention

[0004] In view of this, the present invention aims to propose a core-shell structured rare earth-based wide-temperature conductive powder, its preparation method and application. The conductive powder is a white wide-temperature conductive material that has both room temperature and high temperature conductivity and can be applied to PVC materials to improve the antistatic properties of PVC packaging.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A core-shell structured rare-earth-based wide-temperature conductive powder, wherein the core of the conductive powder's core-shell structure is doped cerium oxide (La). x Re y Ce 1-x-y O2, with a core diameter of 1-3 μm and a shell of antimony tin oxide (ATO) with a thickness of 30-50 nm, is named La. x Re y Ce 1-x-y O2@ATO; where Re is one of Sm, Y, and Nd, and the molar ratio of cerium, lanthanum, and Re is (16-18):(2-2.8):1,0 <x<1,0<y<1,0<x+y<1,x> y.

[0006] The core size determines the particle size. If the core is too large, it will affect the dispersion of the particles in PVC. If the shell thickness is too thin, it cannot completely cover the particles. If it is too thick, the color will be darker and the cost will be high.

[0007] Furthermore, the preparation method of doped cerium oxide is as follows: a. Weigh the cerium source, lanthanum source and Re source in proportion and add them to the flask, then add deionized water and stir until completely dissolved to obtain a mixed solution; b. Heat and stir the mixed solution obtained in step a until the target temperature is reached, then continue stirring. c. Then add alkaline solution dropwise to the system until pH=6, then stop adding alkaline solution and continue stirring. d. Stop heating and stirring, and let it stand to settle until it cools to room temperature; e. The system is filtered to obtain a precipitate, which is then washed with deionized water, dried, and calcined to obtain doped cerium oxide.

[0008] Furthermore, in step a, the cerium source is cerium chloride or cerium nitrate, the lanthanum source is lanthanum chloride or lanthanum nitrate, and the Re source is Re chloride or Re nitrate.

[0009] Furthermore, in step b, the stirring speed is 30-50 r / min, and after reaching the target temperature, stirring continues for 30-60 min, with the target temperature being 50-80℃.

[0010] Furthermore, in step c, the rate of adding the alkaline solution is 10-15 mL / min. After stopping the addition of the alkaline solution, stirring is continued for 60-120 min. The alkaline solution is either 25 wt% ammonia or 10 wt% ammonium bicarbonate.

[0011] Furthermore, in step e, the calcination temperature is 600-900℃, and the calcination time is 5-10h.

[0012] This invention also provides a method for preparing a rare earth-based wide-temperature conductive powder with a core-shell structure as described above, the method comprising the following steps: S1. Preparation of doped cerium oxide; S2. Add doped cerium oxide to an alkaline solution, along with ammonium sulfate and a surfactant, to prepare a mixed suspension slurry. Transfer the slurry to a flask, stir, and heat it to raise the temperature of the reaction system to 50-60℃. S3. Prepare a mixed hydrochloric acid solution of SnCl4·5H2O and SbCl3, and dispense it using a peristaltic pump at a rate of 4-5 mL / min. -1 The solution is added dropwise to the above mixed suspension slurry; after the addition is complete, the temperature is increased to continue the reaction. S4. After the reaction solution is allowed to stand, cooled, filtered, washed, and vacuum dried, a precursor is obtained. The obtained precursor is then ground and calcined in a muffle furnace to obtain rare earth-based wide-temperature conductive powder.

[0013] Further, in step S2, the mass ratio of doped cerium oxide, ammonium sulfate, and surfactant is 20:(6-8):(0.5-0.65), the liquid-to-solid ratio of alkaline solution to doped cerium oxide, ammonium sulfate, and surfactant is 400:(26.5-28.65) mL / g, and the alkaline solution is one of 12.5wt% urea solution, 25wt% ammonia solution, or 25wt% triethanolamine. The surfactant is one of hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, and cocoyltrimethylammonium chloride.

[0014] Furthermore, in step S3, the concentration of the mixed hydrochloric acid solution is 0.2 mol•L. -1 The molar ratio of SnCl4·5H2O to SbCl3 is (9-12):1, and the liquid-to-solid ratio of the mixed hydrochloric acid solution to the doped cerium oxide is (7-8):1mL / g. After the addition is complete, the temperature is raised to 90-120℃, and the reaction continues at this temperature for 4-7 hours. In step S4, vacuum drying is carried out at 60-80℃ for 8-10 hours; calcination is carried out at 600-800℃ for 2-3 hours.

[0015] The present invention also provides an application of the core-shell structured rare earth-based wide-temperature conductive powder as described above in antistatic PVC, wherein the antistatic PVC comprises the following components in parts by weight: 55.5-67 parts of PVC resin, 25-35 parts of rare earth-based wide-temperature conductive powder, 5-8 parts of dispersant, 1-2 parts of toughening agent, and 0.5-1 parts of stabilizer.

[0016] Furthermore, the toughening agent is one of Xingyuan Chemical A-658, Mitsubishi S-2001, and Zhongyuan Chemical MBS S-513; The stabilizer is one of the following: German Bear R 92597 FP, Japanese Mizusawa A-300, and Jiabaite WD-302; The dispersant is one of BYK161, EFKA-4010 and TEGO Dispers 610.

[0017] Furthermore, the preparation steps for antistatic PVC are as follows: (1) Add the raw materials to the high-speed mixer in proportion, set the temperature to 110-130℃, and stir at high speed for 5-15 minutes to ensure that the raw materials are fully mixed; (2) The mixture is melt-extruded and granulated by a twin-screw extruder. The temperature of each zone of the twin-screw extruder is 140℃, 160℃, 170℃, 180℃, and 180℃, the die temperature is 180℃, and the feeding speed is 300-350g / min.

[0018] Compared with existing technologies, the core-shell structured rare earth-based wide-temperature conductive powder, its preparation method, and its applications described in this invention have the following advantages: The rare-earth-based wide-temperature conductive powder of this invention has a core of doped cerium oxide, which has high-temperature conductivity, and an ATO shell layer that imparts room-temperature conductivity to the material. The two work together to give the material both room-temperature and high-temperature conductivity. Simultaneously, the doped cerium oxide can further lighten the color of the ATO shell layer. Through a rare-earth-based white base combined with a thin composite conductive shell design, the material retains its high whiteness and excellent color compatibility, overcoming the dull color defects of traditional carbon-based and metal conductive fillers. It also achieves stable antistatic effects under both room and high-temperature environments, resulting in a wide range of wide-temperature applications. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] In this document, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0021] In this document, when values ​​are described as ranges, it should be understood that such disclosure includes disclosure of all possible subranges within that range, as well as the specific numerical values ​​falling within that range, regardless of whether the specific numerical value or specific subrange is explicitly specified.

[0022] In this article, the terms "multiple" or "more than" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0023] In this document, the terms "preferred" and "more preferred" are used only to describe implementation methods or embodiments with better effects, and should be understood as not constituting a limitation on the scope of protection of this invention.

[0024] In this document, terms such as "further" are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0025] In this article, the term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0026] In this document, the term "about" means a specified value of + / - 10%, preferably + / - 5%, and more preferably + / - 1%.

[0027] In this article, the terms “include,” “including,” “have,” “contain,” etc., are all open-ended terms, meaning that they include but are not limited to.

[0028] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar to or equivalent to those described herein may be used in the implementation or testing of this invention.

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1 The preparation method of rare earth-based wide-temperature conductive powder with core-shell structure includes the following steps: S1. Preparation of doped cerium oxide; a. Take CeCl3·7H2O, LaCl3·7H2O and NdCl3·6H2O in a molar ratio of 18:2:1, add them to a flask, add 500ml of deionized water, and stir with a magnetic stirrer until completely dissolved.

[0031] b. Heat and stir the above solution at a speed of 30 r / min; after reaching the target temperature of 50℃, continue stirring for 30 min.

[0032] c. Add 25wt% ammonia solution dropwise to the system at a rate of 10mL / min until pH=6. Stop adding ammonia solution and continue stirring for 60min.

[0033] d. Stop heating and stirring, and let it stand to settle until it cools to room temperature.

[0034] e. The system is filtered to obtain a precipitate, which is then washed with deionized water, dried, and calcined at 900℃ for 5 hours to obtain lanthanum-neodymium-doped cerium oxide (La). 0.095 Nd 0.048 Ce 0.857 O2, with a particle size of 1-3 μm.

[0035] S2. Weigh 20g of the doped cerium oxide powder prepared in S1 and add it to 400mL of 12.5wt% urea solution. Add 6g of ammonium sulfate and 0.5g of hexadecyltrimethylammonium chloride to form a mixed suspension slurry. Transfer the mixture to a flask, stir and heat it to raise the temperature of the reaction system to 50℃.

[0036] S3, prepare 0.2 mol·L -1A mixed hydrochloric acid solution of SnCl4·5H2O and SbCl3 with a molar ratio of 9:1 was pumped at a rate of 4 mL / min using a peristaltic pump. -1 The solution is added dropwise to the above mixed suspension slurry, with a total addition of 140 mL of mixed hydrochloric acid solution. After the addition is complete, the temperature is raised to 90°C and the reaction continues at this temperature for 7 hours to form an ATO shell with a thickness of 30-50 nm.

[0037] S4. After the reaction solution is allowed to stand, cooled, filtered, and washed, it is vacuum dried at 60℃ for 10 hours to obtain the precursor. The obtained precursor is then thoroughly ground and placed in a muffle furnace for calcination at 800℃ for 2 hours to obtain rare earth-based wide-temperature conductive powder La. 0.095 Nd 0.048 Ce 0.857 O2@ATO.

[0038] The rare earth-based wide-temperature conductive powder provided by this invention is mainly used in antistatic PVC.

[0039] The specific composition of antistatic PVC, by weight, is as follows: 67 parts of PVC resin; 25 parts of rare earth-based wide-temperature conductive powder; Dispersant BYK161, 5 parts; Toughening agent Xingyuan Chemical A-658, 2 parts; Stabilizer German Bear brand R92597FP 1 part.

[0040] The preparation steps for antistatic PVC are as follows: 1. Add the above raw materials to a high-speed mixer in proportion, set the temperature to 110℃, and stir at high speed for 15 minutes to ensure that the raw materials are fully mixed.

[0041] 2. The mixture is melt-extruded and granulated using a twin-screw extruder. The temperatures of each zone of the twin-screw extruder are 140℃, 160℃, 170℃, 180℃, and 180℃, the die temperature is 180℃, and the feeding speed is 300g / min, to obtain antistatic PVC granules.

[0042] Example 2 The preparation method of rare earth-based wide-temperature conductive powder with core-shell structure includes the following steps: S1. Preparation of doped cerium oxide; a. Take CeCl3·7H2O, LaCl3·7H2O and YCl3·6H2O in a molar ratio of 17:2.5:1, add them to a flask, add 500ml of deionized water, and stir with a magnetic stirrer until completely dissolved.

[0043] b. Heat and stir the above solution at a speed of 40 r / min; after reaching the target temperature of 65℃, continue stirring for 40 min.

[0044] c. Add 10wt% ammonium bicarbonate dropwise to the system at 12mL / min until pH=6, then stop adding ammonium bicarbonate and continue stirring for 100min.

[0045] d. Stop heating and stirring, and let it stand to settle until it cools to room temperature.

[0046] e. The system is filtered to obtain a precipitate, which is then washed with deionized water, dried, and calcined at 800℃ for 6 hours to obtain lanthanum-yttrium-doped cerium oxide (La). 0.122 Y 0.049 Ce 0.829 O2, with a particle size of 1-3 μm.

[0047] S2. Weigh 20g of the doped cerium oxide powder prepared in S1, add it to 400mL of 25wt% ammonia water, add 7g of ammonium sulfate and 0.6g of dodecyltrimethylammonium chloride, prepare a mixed suspension slurry, transfer it to a flask, stir and heat it to raise the temperature of the reaction system to 55℃.

[0048] S3, prepare 0.2 mol·L -1 A mixed hydrochloric acid solution of SnCl4·5H2O and SbCl3 with a molar ratio of 10:1 was pumped at a rate of 4.5 mL / min using a peristaltic pump. -1 The solution is added dropwise to the above mixed suspension slurry, with a total addition of 150 mL of mixed hydrochloric acid solution. After the addition is complete, the temperature is raised to 100°C and the reaction continues at this temperature for 6 hours to form an ATO shell with a thickness of 30-50 nm.

[0049] S4. After the reaction solution is allowed to stand, cooled, filtered, and washed, it is vacuum dried at 70℃ for 9 hours to obtain the precursor. The obtained precursor is then thoroughly ground and placed in a muffle furnace for calcination at 700℃ for 2.5 hours to obtain rare earth-based wide-temperature conductive powder La. 0.122 Y 0.049 Ce 0.829 O2@ATO.

[0050] The rare earth-based wide-temperature conductive powder provided by this invention is mainly used in antistatic PVC.

[0051] The specific composition of antistatic PVC, by weight, is as follows: 60 parts of PVC resin; 32 parts of rare earth-based wide-temperature conductive powder; Dispersant EFKA-4010, 6 parts; Toughening agent Mitsubishi S-2001 1.2 parts; Stabilizer: 0.8 parts of Mizusawa A-300 (Japan); The preparation steps for antistatic PVC are as follows: 1. Add the above raw materials to a high-speed mixer in proportion, set the temperature to 120℃, and stir at high speed for 10 minutes to ensure that the raw materials are fully mixed.

[0052] 2. The mixture is melt-extruded and granulated using a twin-screw extruder. The temperatures of each zone of the twin-screw extruder are 140℃, 160℃, 170℃, 180℃, and 180℃, the die temperature is 180℃, and the feeding speed is 320g / min, to obtain antistatic PVC granules.

[0053] Example 3 The preparation method of rare earth-based wide-temperature conductive powder with core-shell structure includes the following steps: S1. Preparation of doped cerium oxide; a. Take CeCl3·7H2O, LaCl3·7H2O and SmCl3·6H2O in a molar ratio of 16:2.8:1, add them to a flask, add 500ml of deionized water, and stir with a magnetic stirrer until completely dissolved.

[0054] b. Heat and stir the above solution at a speed of 50 r / min; after reaching the target temperature of 80℃, continue stirring for 60 min.

[0055] c. Add 25wt% ammonia solution dropwise to the system at a rate of 15mL / min until pH=6. Stop adding ammonia solution and continue stirring for 120min.

[0056] d. Stop heating and stirring, and let it stand to settle until it cools to room temperature.

[0057] e. The system is filtered to obtain a precipitate, which is then washed with deionized water, dried, and calcined at 600℃ for 10 hours to obtain lanthanum-samarium-doped cerium oxide (La). 0.141 Sm 0.051 Ce 0.808 O2, with a particle size of 1-3 μm.

[0058] S2. Weigh 20g of the doped cerium oxide powder prepared in S1, add it to 400mL of 25wt% triethanolamine, add 8g of ammonium sulfate and 0.65g of cocoyl trimethylammonium chloride, prepare a mixed suspension slurry, transfer it to a flask, stir and heat it to raise the temperature of the reaction system to 60℃.

[0059] S3, prepare 0.2 mol·L -1 A mixed hydrochloric acid solution of SnCl4·5H2O and SbCl3 with a molar ratio of 12:1 was pumped at a rate of 5 mL / min using a peristaltic pump. -1The solution was added dropwise to the above mixed suspension slurry, with a total addition of 160 mL of mixed hydrochloric acid solution. After the addition was complete, the temperature was raised to 120°C, and the reaction was continued at this temperature for 4 hours to form an ATO shell with a thickness of 30-50 nm.

[0060] S4. After the reaction solution is allowed to stand, cooled, filtered, and washed, it is vacuum dried at 80℃ for 8 hours to obtain the precursor. The obtained precursor is then thoroughly ground and placed in a muffle furnace for calcination at 600℃ for 3 hours to obtain rare earth-based wide-temperature conductive powder La. 0.141 Sm 0.051 Ce 0.808 O2@ATO.

[0061] The rare earth-based wide-temperature conductive powder provided by this invention is mainly used in antistatic PVC.

[0062] The specific composition of antistatic PVC, by weight, is as follows: 55.5 parts of PVC resin; 35 parts of rare earth-based wide-temperature conductive powder; 8 parts of TEGO Dispers 610 dispersant; One part of toughening agent Zhongyuan Chemical MBS S-513; Stabilizer Jiabaite WD-302 0.5 parts.

[0063] The preparation steps for antistatic PVC are as follows: 1. Add the above raw materials to a high-speed mixer in proportion, set the temperature to 130℃, and stir at high speed for 5 minutes to ensure that the raw materials are fully mixed.

[0064] 2. The mixture is melt-extruded and granulated using a twin-screw extruder. The temperatures of each zone of the twin-screw extruder are 140℃, 160℃, 170℃, 180℃, and 180℃, the die temperature is 180℃, and the feeding speed is 350g / min, to obtain antistatic PVC granules.

[0065] Comparative Example 1 The difference from Example 1 is that rare earth-based wide-temperature conductive powder is not added when preparing antistatic PVC. The preparation method is the same as in Example 1.

[0066] Comparative Example 2 The difference from Example 1 is that NdCl3·6H2O was replaced with ErCl3·6H2O to prepare doped cerium oxide La. 0.095 Er 0.048 Ce 0.857 O2 was used to prepare rare earth-based wide-temperature conductive powder using the same method as in Example 1, and then the rare earth-based wide-temperature conductive powder was used to prepare antistatic PVC.

[0067] Comparative Example 3 The difference from Example 1 is that the rare earth-based wide-temperature conductive powder has no shell layer, and the surface of the doped cerium oxide is not coated with ATO. That is, the doped cerium oxide prepared is directly used for the preparation of antistatic PVC. Other steps are the same as in Example 1.

[0068] Comparative Example 4 The difference from Example 1 is that the rare earth-based wide-temperature conductive powder has no core and only contains ATO. That is, when preparing antistatic PVC, the rare earth-based wide-temperature conductive powder is replaced with ATO. Everything else is the same as in Example 1.

[0069] The preparation steps for ATO are as follows: 1. Add 6g of ammonium sulfate and 0.5g of hexadecyltrimethylammonium chloride to 400mL of 12.5wt% urea solution to prepare a mixed suspension. Transfer the suspension to a flask, stir, and heat to raise the temperature of the reaction system to 50℃.

[0070] 2. Prepare 0.2 mol·L -1 A mixed hydrochloric acid solution of SnCl4·5H2O and SbCl3 with a molar ratio of 9:1 was pumped at a rate of 4 mL / min using a peristaltic pump. -1 The solution was added dropwise to the above mixed suspension, with a total addition of 140 mL. After the addition was complete, the temperature was raised to 90°C, and the reaction was continued at this temperature for 7 hours.

[0071] 3. After the reaction solution is allowed to stand, cooled, filtered, and washed, it is vacuum dried at 60°C for 10 hours to obtain the precursor. The obtained precursor is then thoroughly ground, placed in a muffle furnace, and calcined at 800°C for 2 hours to obtain ATO powder.

[0072] Comparative Example 5 The difference from Example 1 is that doped cerium oxide and ATO were prepared separately, and then the doped cerium oxide and ATO were simply mixed evenly to obtain rare earth-based wide-temperature conductive powder, which was then used to prepare PVC. The ATO preparation process was the same as in Comparative Example 4. Other steps were the same as in Example 1.

[0073] Comparative Example 6 The difference from Example 1 is that, in preparing the rare-earth-based wide-temperature conductive powder, the core was not doped; cerium oxide was used as the core. The preparation steps are as follows: 1. Weigh 21g CeCl3·7H2O, add it to a flask, then add 500ml of deionized water, and stir with a magnetic stirrer until completely dissolved.

[0074] 2. Heat and stir the above solution at 50°C and 30 r / min; after reaching the target temperature, continue stirring for 30 min.

[0075] 3. Slowly add 25wt% ammonia solution to the system until pH=6, then stop adding ammonia solution and continue stirring for 60 minutes.

[0076] 4. Stop heating and stirring, and let it stand to settle until it cools to room temperature.

[0077] 5. The system is filtered to obtain a precipitate, which is then washed and dried with deionized water, and then calcined at 900℃ for 5 hours to obtain cerium oxide.

[0078] The other steps are the same as in Example 1.

[0079] Comparative Example 7 The difference from Example 1 is that, in the preparation of rare earth-based wide-temperature conductive powder, the surfactant hexadecyltrimethylammonium chloride is replaced with oleic acid, while the other steps are the same as in Example 1.

[0080] Comparative Example 8 The difference from Example 1 is that the molar ratio of cerium, lanthanum and Re is different. CeCl3·7H2O, LaCl3·7H2O and NdCl3·6H2O are taken in a molar ratio of 22:4:1. The other steps are the same as in Example 1.

[0081] Comparative Example 9 The difference from Example 1 is that Re is not used; CeCl3·7H2O and LaCl3·7H2O are used in a molar ratio of 18:2, and NdCl3·6H2O is not added. The other steps are the same as in Example 1.

[0082] Comparative Example 10 The difference from Example 1 is that lanthanum is not used; CeCl3·7H2O and NdCl3·6H2O are used in a molar ratio of 18:1, and LaCl3·7H2O is not added. The other steps are the same as in Example 1.

[0083] Comparative Example 11 The difference from Example 1 is that, during the coating process, the prepared mixed hydrochloric acid solution contained only SnCl4·5H2O and no SbCl3. The specific steps are as follows: S2. Weigh 20g of the doped cerium oxide powder prepared in S1 and add it to 400mL of 12.5wt% urea solution. Add 6g of ammonium sulfate and 0.5g of hexadecyltrimethylammonium chloride to form a mixed suspension slurry. Transfer the mixture to a flask, stir and heat it to raise the temperature of the reaction system to 50℃.

[0084] S3, prepare 0.2 mol·L -1 SnCl4·5H2O hydrochloric acid solution, dispensed via a peristaltic pump at a rate of 4 mL / min -1The solution is added dropwise to the above mixed suspension slurry, with a total addition of 140 mL. After the addition is complete, the temperature is raised to 90 °C and the reaction continues at this temperature for 7 hours to form a SnO2 shell with a thickness of 30-50 nm.

[0085] S4. After the reaction solution is allowed to stand, cooled, filtered, and washed, it is vacuum dried at 60℃ for 10 hours to obtain the precursor. The obtained precursor is then thoroughly ground and placed in a muffle furnace for calcination at 800℃ for 2 hours to obtain rare earth-based wide-temperature conductive powder La. 0.095 Nd 0.048 Ce 0.857 O2@SnO2.

[0086] The rare-earth-based wide-temperature conductive powders of each embodiment and comparative example, as well as the antistatic PVC prepared using them as raw materials, were tested. The room-temperature conductivity and high-temperature conductivity (100℃) and whiteness of the conductive powders, and the room-temperature conductivity and high-temperature conductivity (100℃) of the PVC particles were tested respectively. No filler was used in Comparative Example 1, so no related powder tests were performed. The test results of Examples 1-3 and Comparative Examples 1-11 provided by this invention are shown in Table 1.

[0087] Table 1 Test Results

[0088] As shown in Table 1, the room temperature conductivity of the powders in Examples 1-3 of this invention is around 0.2 S / cm, the high temperature conductivity is above 0.55 S / cm, and the whiteness is above 80%. The room temperature conductivity of PVC is above 10. -8 The above indicates that the high-temperature conductivity of PVC is above 10. -6 above.

[0089] Compared to Example 1, Comparative Example 1 did not add rare earth-based wide-temperature conductive powder as a filler. Its PVC room temperature conductivity and high temperature conductivity were significantly lower than those of Example 1, indicating that the rare earth-based wide-temperature conductive powder played a role in improving the conductivity of the PVC matrix at different temperatures.

[0090] Compared with Example 1, Comparative Example 2 prepared a conductive powder core layer by replacing Nd with Er. Its powder conductivity and PVC conductivity were slightly lower than those of Example 1. Moreover, compared with Examples 2-3, its powder conductivity and PVC conductivity were also reduced. This shows that only when Re is one of Sm, Y and Nd can it have better conductivity. Not any rare earth doping can bring good conductivity. The Re selected in this invention was obtained through experimental screening.

[0091] Compared to Example 1, Comparative Example 3 did not have an ATO shell coating and only used lanthanum-neodymium-doped cerium oxide as a filler. Although its high-temperature conductivity and whiteness were slightly higher than those of Example 1, its room-temperature conductivity was much lower than that of Example 1. It was difficult to maintain the antistatic properties of PVC at room temperature, indicating that the ATO shell significantly improved the room-temperature conductivity of the powder and PVC.

[0092] Compared to Example 1, the rare earth-based wide-temperature conductive powder in Comparative Example 4 has no core and only contains ATO. Since no doped cerium oxide was added, its whiteness is significantly lower than that of Example 1, and the high-temperature conductivity of its powder and PVC is also lower than that of Example 1. This indicates that the doped cerium oxide improved the whiteness of the powder and provided high-temperature conductivity.

[0093] Compared with Example 1, Comparative Example 5 did not form a core-shell structure in its conductive powder. It simply mixed doped cerium oxide with ATO to form a rare earth-based wide-temperature conductive powder. Its high-temperature conductivity, room-temperature conductivity, and whiteness were all lower than those of Example 1, indicating that the core-shell structure of the conductive powder played a role in improving whiteness and conductivity.

[0094] Compared with Example 1, Comparative Example 6 did not dope the core, i.e., it prepared conductive powder with cerium oxide as the core and ATO as the shell. Its whiteness was slightly lower than that of Example 1, and its high-temperature conductivity was significantly lower than that of Example 1, indicating that element doping plays an important role in improving the high-temperature conductivity of conductive powder.

[0095] Compared to Example 1, Comparative Example 7 used a surfactant outside the protection range when preparing rare earth-based wide-temperature conductive powder. Its room temperature and high temperature conductivity and whiteness were significantly reduced, mainly due to the reduced uniformity of the shell coating. This indicates that a suitable surfactant is the key to synthesizing core-shell type rare earth-based wide-temperature conductive powder.

[0096] Compared to Example 1, the La:Ce:Nd ratio in Doped Cerium Oxide 8 is 22:4:1, which does not satisfy (16-18):(2-2.8):1. The high-temperature conductivity of its powder and PVC is slightly lower than that of Example 8. This shows that each rare earth element needs to meet a specific ratio range in order to ensure that the product maintains a high conductivity level to the greatest extent. It also shows that the core layer doped Cerium Oxide mainly determines the high-temperature conductivity of the product.

[0097] Compared with Example 1, in the synthesis of doped cerium oxide, only CeCl3·7H2O and LaCl3·7H2O were added to the rare earth raw materials in Comparative Example 9, that is, only La doping was carried out and Nd doping was not carried out. The high temperature conductivity of the powder and the high temperature conductivity of PVC were lower than those of Example 1, indicating that Nd doping plays an important role in improving the high temperature conductivity of the product.

[0098] Compared with Example 1, in the synthesis of doped cerium oxide, only CeCl3·7H2O and NdCl3·6H2O were added to the rare earth raw materials in Comparative Example 10, that is, only Nd doping was carried out and La doping was not carried out. The high-temperature conductivity of the powder and the high-temperature conductivity of PVC were lower than those of Example 10, and the degree of decrease was greater than that of Comparative Example 9. This indicates that La doping has a greater effect on improving conductivity by increasing electron density than Nd doping.

[0099] Compared with Example 1, Comparative Example 11 has a shell of SnO2, i.e. no Sb doping. Its high-temperature conductivity of powder, high-temperature conductivity of PVC and whiteness are significantly reduced, indicating that Sb doping plays an important role in improving the room temperature conductivity and whiteness of the product.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A core-shell structured rare-earth-based wide-temperature conductive powder, characterized in that, The core of the conductive powder's core-shell structure is doped cerium oxide (La). x Re y Ce 1-x-y O2, with a core diameter of 1-3 μm and a shell of antimony tin oxide (ATO) with a thickness of 30-50 nm, is named La. x Re y Ce 1-x-y O2@ATO; where Re is one of Sm, Y, and Nd, and the molar ratio of cerium, lanthanum, and Re is (16-18):(2-2.8):1,0 <x<1,0<y<1,0<x+y<1,x> y.

2. The rare-earth-based wide-temperature conductive powder with a core-shell structure according to claim 1, characterized in that, The preparation method of doped cerium oxide is as follows: a. Weigh the cerium source, lanthanum source and Re source in proportion and add them to the flask, then add deionized water and stir until completely dissolved to obtain a mixed solution; b. Heat and stir the mixed solution obtained in step a until the target temperature is reached, then continue stirring. c. Then add alkaline solution dropwise to the system until pH=6, then stop adding alkaline solution and continue stirring. d. Stop heating and stirring, and let it stand to settle until it cools to room temperature; e. The system is filtered to obtain a precipitate, which is then washed with deionized water, dried, and calcined to obtain doped cerium oxide.

3. The rare earth-based wide-temperature conductive powder with a core-shell structure according to claim 2, characterized in that, In step a, the cerium source is cerium chloride or cerium nitrate, the lanthanum source is lanthanum chloride or lanthanum nitrate, and the Re source is Re chloride or Re nitrate.

4. The rare-earth-based wide-temperature conductive powder with a core-shell structure according to claim 2, characterized in that, In step b, the stirring speed is 30-50 r / min, and after reaching the target temperature, stirring continues for 30-60 min, with the target temperature being 50-80℃.

5. The rare-earth-based wide-temperature conductive powder with a core-shell structure according to claim 2, characterized in that, In step c, the alkaline solution is added dropwise at a rate of 10-15 mL / min. After stopping the addition of the alkaline solution, stirring is continued for 60-120 min. The alkaline solution is either 25 wt% ammonia or 10 wt% ammonium bicarbonate.

6. The rare-earth-based wide-temperature conductive powder with a core-shell structure according to claim 2, characterized in that, In step e, the calcination temperature is 600-900℃ and the calcination time is 5-10h.

7. A method for preparing a rare-earth-based wide-temperature conductive powder with a core-shell structure as described in any one of claims 1-6, characterized in that, The method includes the following steps: S1. Preparation of doped cerium oxide; S2. Add doped cerium oxide to an alkaline solution, along with ammonium sulfate and a surfactant, to prepare a mixed suspension slurry. Transfer the slurry to a flask, stir, and heat it to raise the temperature of the reaction system to 50-60℃. S3. Prepare a mixed hydrochloric acid solution of SnCl4·5H2O and SbCl3, and dispense it using a peristaltic pump at a rate of 4-5 mL / min. -1 The solution is added dropwise to the above mixed suspension slurry; after the addition is complete, the temperature is increased to continue the reaction. S4. After the reaction solution is allowed to stand, cooled, filtered, washed, and vacuum dried, a precursor is obtained. The obtained precursor is then ground and calcined in a muffle furnace to obtain rare earth-based wide-temperature conductive powder.

8. The method for preparing the core-shell structured rare earth-based wide-temperature conductive powder according to claim 7, characterized in that, In step S2, the mass ratio of doped cerium oxide, ammonium sulfate, and surfactant is 20:(6-8):(0.5-0.65), and the liquid-to-solid ratio of alkaline solution to doped cerium oxide, ammonium sulfate, and surfactant is 400:(26.5-28.65) mL / g. The alkaline solution is one of 12.5wt% urea solution, 25wt% ammonia solution, or 25wt% triethanolamine. The surfactant is one of hexadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, and cocoyltrimethylammonium chloride.

9. The method for preparing the core-shell structured rare earth-based wide-temperature conductive powder according to claim 7, characterized in that, In step S3, the concentration of the mixed hydrochloric acid solution is 0.2 mol•L. -1 The molar ratio of SnCl4·5H2O to SbCl3 is (9-12):1, and the liquid-to-solid ratio of the mixed hydrochloric acid solution to the doped cerium oxide is (7-8):1mL / g. After the addition is complete, the temperature is raised to 90-120℃, and the reaction continues at this temperature for 4-7 hours. In step S4, vacuum drying is carried out at 60-80℃ for 8-10 hours; calcination is carried out at 600-800℃ for 2-3 hours.

10. The application of a rare earth-based wide-temperature conductive powder with a core-shell structure as described in any one of claims 1-6 in antistatic PVC, characterized in that, The antistatic PVC comprises the following components in parts by weight: 55.5-67 parts PVC resin, 25-35 parts rare earth-based wide-temperature conductive powder, 5-8 parts dispersant, 1-2 parts toughening agent, and 0.5-1 part stabilizer.

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