Antistatic flame-retardant PA5T / 56 composite material and preparation method thereof

Abstract

The invention discloses an antistatic flame-retardant PA5T / 56 composite material and a preparation method thereof, and relates to the technical field of high polymer materials, the composite material comprises the following components by mass: 45%-60% of PA5T / 56 resin, 20%-40% of glass fiber, 10%-15% of silane modified nano carbon black, 5%-10% of stearic acid modified nano calcium carbonate, and 0.5%-2% of an antioxidant. The silane modified nano carbon black and the stearic acid modified nano calcium carbonate are compounded to play a synergistic enhancement role, so that the antistatic property and the flame retardant property of the PA5T / 56 material can be effectively improved; load is transmitted and stress is dispersed through interface combination of the glass fiber and the PA5T / 56 matrix, so that the rigidity of the material is improved; and by adding the antioxidant, the thermal stability of the composite material can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to an anti-static flame-retardant PA5T / 56 composite material and a preparation method thereof. Background Art

[0002] With growing awareness of environmental and non-renewable resource protection, significant progress has been made in the development and application of bio-based monomers, driving the diversified development of bio-based amide materials. Currently, materials such as PA5T and PA10T synthesized from bio-based monomers have been widely used in the market and have demonstrated excellent performance.

[0003] PA5T / 56 is a high-performance semi-aromatic polyamide material that combines the properties of PA5T (polypentamethylene terephthalamide) and PA56 (polypentamethylene adipamide). It can maintain good mechanical properties and heat resistance under high temperature and high pressure. To further enhance its performance, glass fiber is usually used to reinforce it to increase the mechanical strength, rigidity and thermal stability of the material. However, traditional glass fiber reinforced PA5T / 56 composite materials have obvious limitations: on the one hand, its surface resistivity is as high as 10 15 Ω, it is easy to accumulate static electricity, which may interfere with sensitive components in electronic and electrical applications; on the other hand, its flame retardant performance is difficult to meet the strict UL94-V0 standard, limiting its application in electronic equipment structural parts, automotive electrical components, etc.

[0004] Therefore, developing a PA5T / 56 composite material with high strength, antistatic and excellent flame retardant properties has become a technical problem that needs to be solved urgently in the current materials field. Summary of the Invention

[0005] The object of the present invention is to provide an anti-static flame-retardant PA5T / 56 composite material and a preparation method thereof, so as to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the first aspect of the present invention provides an anti-static and flame-retardant PA5T / 56 composite material, which comprises the following components, by mass percentage: 45%-60% PA5T / 56 resin, 20%-40% glass fiber, 10%-15% silane-modified nano-carbon black, 5%-10% stearic acid-modified nano-calcium carbonate, and 0.5%-2% antioxidant.

[0007] In the first aspect, the glass fiber is surface-treated chopped glass fiber.

[0008] In the first aspect, the preparation method of the silane-modified nano-carbon black includes: placing nano-carbon black in isopropanol and ultrasonically dispersing it to obtain a nano-carbon black / isopropanol suspension; dissolving a silane coupling agent in anhydrous ethanol and ultrasonically dispersing it to obtain a silane coupling agent / ethanol mixed solution; placing the nano-carbon black / isopropanol suspension and the silane coupling agent / ethanol mixed solution in a three-necked flask and stirring them at 90-100° C. for 4-6 hours to obtain a reaction solution; filtering, washing, and drying the reaction solution to obtain silane-modified nano-carbon black.

[0009] In the first aspect, the volume ratio of the silane coupling agent to the anhydrous ethanol is 1:100-2:100; and the added amount of the silane coupling agent is 10-20% of the mass of the nano carbon black.

[0010] In a first aspect, the preparation method of the stearic acid-modified nano-calcium carbonate comprises: placing nano-calcium carbonate in anhydrous ethanol and ultrasonically dispersing the nano-calcium carbonate to obtain a nano-calcium carbonate / ethanol suspension; ultrasonically dispersing stearic acid and anhydrous ethanol at a volume ratio of 1:100-5:100 at 45-50° C. and fully dissolving the mixture to obtain a stearic acid / ethanol solution; placing the nano-calcium carbonate / ethanol suspension and the stearic acid / ethanol solution in a three-necked flask and stirring the mixture at 60-80° C. for 1-2 hours to obtain a reaction solution; and filtering, washing, drying, and grinding the reaction solution to obtain the stearic acid-modified nano-calcium carbonate.

[0011] In the first aspect, the added amount of the stearic acid is 2-5% of the mass of the nano-calcium carbonate.

[0012] In the first aspect, the antioxidant is N,N′-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine.

[0013] A second aspect of the present invention provides a method for preparing an anti-static flame-retardant PA5T / 56 composite material, the preparation method comprising: preparing silane-modified nano-carbon black; preparing stearic acid-modified nano-calcium carbonate; weighing the raw material components of the composite material, the raw material components comprising: 45%-60% A5T / 56 resin, 20%-40% glass fiber, 10%-15% silane-modified nano-carbon black, 5%-10% stearic acid-modified nano-calcium carbonate and 0.5%-2% antioxidant; pre-mixing the A5T / 56 resin, the silane-modified nano-carbon black, the stearic acid-modified nano-calcium carbonate and the antioxidant to obtain an initial mixture; adding the initial mixture from a main feeding hopper and conveying it into the screw cavity of a twin-screw extruder, adding the glass fiber from a side feeding hopper and conveying it into the screw cavity of the twin-screw extruder, heating and melting, extruding and granulating, to obtain the anti-static flame-retardant PA5T / 56 composite material.

[0014] In the second aspect, the preparation of silane-modified nano-carbon black specifically includes: weighing nano-carbon black and a silane coupling agent with a mass fraction of 10-20% respectively; placing the nano-carbon black in isopropanol and ultrasonically dispersing it to obtain a nano-carbon black / isopropanol suspension; ultrasonically dispersing a silane coupling agent and anhydrous ethanol with a volume ratio of 1:100-2:100 to obtain a silane coupling agent / ethanol mixed solution; placing the nano-carbon black / isopropanol suspension and the silane coupling agent / ethanol mixed solution in a three-necked flask and stirring at 90-100°C for 4-6h to obtain a reaction solution; filtering and washing the reaction solution to obtain a filter cake; and drying the filter cake in a vacuum drying oven at 100°C to obtain silane-modified nano-carbon black.

[0015] In the second aspect, the preparation of stearic acid-modified nano-calcium carbonate specifically includes: weighing nano-calcium carbonate and stearic acid with a mass fraction of 2-5% respectively; placing the nano-calcium carbonate in anhydrous ethanol and ultrasonically dispersing to obtain a nano-calcium carbonate / ethanol suspension; ultrasonically dispersing stearic acid and anhydrous ethanol with a volume ratio of 1:100-5:100 at 45-50°C and fully dissolving to obtain a stearic acid / ethanol solution; placing the nano-calcium carbonate / ethanol suspension and the stearic acid / ethanol solution in a three-necked flask and stirring at 60-80°C for 1-2h to obtain a reaction liquid; filtering and washing the reaction liquid to obtain a filter cake; placing the filter cake in a vacuum drying oven at 100°C for drying, and grinding to obtain stearic acid-modified nano-calcium carbonate.

[0016] Beneficial effects: The present invention provides an anti-static flame-retardant PA5T / 56 composite material, which comprises, by mass percentage, 45%-60% of PA5T / 56 resin, 20%-40% of glass fiber, 10%-15% of silane-modified nano-carbon black, 5%-10% of stearic acid-modified nano-calcium carbonate, and 0.5%-2% of an antioxidant; the PA5T / 56 composite material is modified to be anti-static and flame-retardant by surface-modifying the nano-carbon black and nano-calcium carbonate and compounding the two. The surface-modified silane-modified nano-carbon black can be evenly dispersed in the resin to form a conductive path, thereby reducing the surface resistivity of the material, and can also capture free radicals during the combustion process to improve the flame retardant properties of the material; the surface-modified stearic acid-modified nano-calcium carbonate has good interfacial compatibility with the PA5T / 56 resin, and can exert a synergistic effect with the silane-modified nano-carbon black in the resin matrix to jointly construct a smoother conductive path and achieve synergistic flame retardancy through the gas phase and condensed phase. The combination of silane-modified nanocarbon black and stearic acid-modified nanocalcium carbonate can reduce the amount of conductive or flame-retardant material required, lowering costs while also achieving a synergistic reinforcement effect. Furthermore, the addition of glass fiber and antioxidants can effectively improve the material's rigidity and high-temperature resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 The present invention provides a flow chart of a method for preparing an anti-static and flame-retardant PA5T / 56 composite material. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below in conjunction with specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly presented. It should be understood by those skilled in the art that these specific embodiments and examples are for illustrating the present invention, rather than for limiting the present invention.

[0020] Throughout this specification, unless otherwise specified, the terms used herein should be understood as having the same meaning as commonly used in the art. Therefore, 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 invention belongs. In the event of any conflict, the present specification shall take precedence.

[0021] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or obtained through existing methods.

[0022] The present invention provides an anti-static and flame-retardant PA5T / 56 composite material. The composite material comprises the following components, measured by mass percentage: 45%-60% of PA5T / 56 resin, 20%-40% of glass fiber, 10%-15% of silane-modified nano-carbon black, 5%-10% of stearic acid-modified nano-calcium carbonate, and 0.5%-2% of an antioxidant.

[0023] The glass fiber is surface-treated chopped glass fiber.

[0024] As one embodiment, the preparation method of silane-modified nano-carbon black includes: placing nano-carbon black in isopropanol, ultrasonically dispersing it, and obtaining a nano-carbon black / isopropanol suspension; dissolving a silane coupling agent in anhydrous ethanol, ultrasonically dispersing it, and obtaining a silane coupling agent / ethanol mixed solution; placing the nano-carbon black / isopropanol suspension and the silane coupling agent / ethanol mixed solution in a three-necked flask, and stirring at 90-100°C for 4-6h to obtain a reaction solution; filtering, washing, and drying the reaction solution to obtain silane-modified nano-carbon black.

[0025] The volume ratio of the silane coupling agent to the anhydrous ethanol is 1:100-2:100; the added amount of the silane coupling agent is 10-20% of the mass of the nano carbon black.

[0026] As one embodiment, the preparation method of stearic acid-modified nano-calcium carbonate includes: placing nano-calcium carbonate in anhydrous ethanol, ultrasonically dispersing, and obtaining a nano-calcium carbonate / ethanol suspension; ultrasonically dispersing stearic acid and anhydrous ethanol at a volume ratio of 1:100-5:100 at 45-50°C, fully dissolving, and obtaining a stearic acid / ethanol solution; placing the nano-calcium carbonate / ethanol suspension and the stearic acid / ethanol solution in a three-necked flask, and stirring at 60-80°C for 1-2h to obtain a reaction solution; filtering, washing, drying, and grinding the reaction solution to obtain stearic acid-modified nano-calcium carbonate.

[0027] The added amount of the stearic acid is 2-5% of the mass of the nano-calcium carbonate.

[0028] As one embodiment, the antioxidant is N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine.

[0029] Based on a general inventive concept, such as Figure 1 As shown, the second aspect of the present invention provides a method for preparing an anti-static flame-retardant PA5T / 56 composite material, the preparation method comprising: S1, preparing silane-modified nano-carbon black; S2, preparing stearic acid modified nano calcium carbonate; S3. Weighing the raw material components of the composite material, wherein the raw material components include: 45%-60% A5T / 56 resin, 20%-40% glass fiber, 10%-15% silane-modified nano-carbon black, 5%-10% stearic acid-modified nano-calcium carbonate, and 0.5%-2% antioxidant; S4, premixing the A5T / 56 resin, the silane-modified nano-carbon black, the stearic acid-modified nano-calcium carbonate, and the antioxidant to obtain an initial mixture; S5. Add the initial mixture from the main hopper and convey it into the screw cavity of a twin-screw extruder. Add the glass fiber from the side hopper and convey it into the screw cavity of the twin-screw extruder. After heating, melting, extrusion and granulation, an anti-static and flame-retardant PA5T / 56 composite material is obtained. The processing temperature of the twin-screw extruder is controlled at 300-325° C. and the main engine speed is 370-430 rpm.

[0030] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present application only and are not intended to limit the scope of the present application. The experimental methods in the following examples where specific conditions are not specified are usually measured in accordance with national standards. If there are no corresponding national standards, then the methods are carried out in accordance with general international standards, conventional conditions, or according to the conditions recommended by the manufacturer.

[0031] The raw materials used in the examples and comparative examples are as follows: PA5T / 56 resin: homemade, the molar ratio of PA5T and PA56 structural units is 3 / 2, and its melting point is about 310℃.

[0032] Glass fiber: Chopped glass fiber surface treated with silane-based sizing; China Jushi Co., Ltd., ECS11-03-560A chopped glass fiber.

[0033] Nano carbon black: Shanghai Buding Chemical Co., Ltd., Cabot N220; Silane-modified nanocarbon black: Weigh an appropriate amount of nanocarbon black and 10-20% by mass of KH550 silane coupling agent, dissolve the carbon black in isopropanol, and ultrasonically disperse for 30 minutes to prepare a nanocarbon black / isopropanol suspension; then prepare a mixture of KH550 silane coupling agent and anhydrous ethanol in a volume ratio of 1:100, and ultrasonically disperse for 30 minutes to prepare a silane coupling agent / ethanol mixed solution; the nanocarbon black / isopropanol suspension and the silane coupling agent / ethanol mixed solution are placed in a three-necked flask, mixed, and stirred at 90°C for 4 hours, filtered, washed with anhydrous ethanol several times, and dried in a vacuum drying oven at 100°C to constant weight to obtain silane-modified nanocarbon black.

[0034] Nano calcium carbonate: Shanghai Liangjiang Titanium Dioxide Chemical Products Co., Ltd., LP-600, average path length 15-40 nm; Stearic acid-modified nano-calcium carbonate: Weigh an appropriate amount of nano-calcium carbonate and stearic acid with a mass fraction of 2-5%, dissolve the nano-calcium carbonate in anhydrous ethanol, and ultrasonically disperse for 30 minutes to prepare a nano-calcium carbonate / ethanol suspension. Then, prepare a mixture of stearic acid and anhydrous ethanol in a volume ratio of 1-100, and ultrasonically disperse at 45°C for 30 minutes to fully dissolve the stearic acid to prepare a stearic acid / ethanol solution. Place the nano-calcium carbonate / ethanol suspension and the stearic acid / ethanol solution in a three-necked flask, mix, stir at 60°C for 2 hours, filter, dry in a vacuum drying oven at 100°C, and grind to obtain stearic acid-modified nano-calcium carbonate.

[0035] Antioxidant: Tianjin Li’anlong New Materials Co., Ltd., RIANOX-1098.

[0036] The raw material components in Examples 1-3 and Comparative Examples 1-5 of the present invention are shown in Table 1 below in terms of mass percentage: Table 1 Distribution ratio of each group of raw materials The formulation ratios provided in Examples 1-3 and Comparative Examples 1-5 were used to prepare PA5T / 56 composite materials according to the following experimental steps: (1) Weigh the raw material components according to the respective formula ratios of the examples and comparative examples. The PA5T / 56 resin needs to be dried at 120°C for 2 hours before weighing. (2) Premixing the weighed PA5T / 56 resin, silane-modified nano-carbon black, stearic acid-modified nano-calcium carbonate, and antioxidant to obtain an initial mixture; (3) The initial mixed material is fed into the main feeding hopper of the twin-screw extruder and transported by its own gravity and the screw of the first feeding zone of the extruder. At the same time, the glass fiber is added to the hopper of the side feeder and transported to the screw cavity of the extruder through the screw of the side feeder. After heating and melting by the heating barrel and screw shearing, the extruder is extruded and granulated. The processing temperature of the twin-screw extruder is controlled at 300-325℃ and the main engine speed is 370-430rpm, and finally the PA5T / 56 material is obtained.

[0037] The performance of the PA5T / 56 composite materials prepared in Examples 1-3 and Comparative Examples 1-5 was tested, and the test results are shown in Table 2 below: Table 2 Test results The experimental data above demonstrates that Examples 1-3 of the present invention develop anti-static flame-retardant PA5T / 56 composite materials using varying proportions of PA5T / 56 resin, glass fiber, silane-modified nanocarbon black, stearic acid-modified nanocalcium carbonate, and an antioxidant. Nanocarbon black is a functional filler with heat resistance, flame retardancy, and electrical conductivity. It not only contains free electrons within its interior but also possesses polymerization inhibitory groups on its surface. After surface modification with a silane coupling agent, the nanocarbon black is uniformly dispersed within the PA5T / 56 matrix. The particles interact to form a smooth, three-dimensional conductive network, providing a migration path for static charges, preventing charge accumulation and effectively improving electrical conductivity. Furthermore, during combustion, the nanocarbon black forms a dense carbon layer that coats the polymer surface, forming a protective layer that suppresses smoke release, reduces oxygen exchange, and enhances the material's flame retardancy. Nano-calcium carbonate has a unique crystal structure and surface electronic structure. After being surface-modified with stearic acid, it is evenly dispersed in the PA5T / 56 matrix, which can improve hygroscopicity and ionic conductivity. At the same time, calcium carbonate decomposes at high temperatures to produce calcium oxide and water vapor. Calcium oxide covering the surface of the material can also act as a barrier. Water vapor can not only dilute the concentration of combustible vapors, but also exert its flame retardant effect in the condensed phase. The combined use of silane-modified nano-carbon black and stearic acid-modified nano-calcium carbonate has a synergistic enhancement effect, which can effectively improve the antistatic and flame retardant properties of PA5T / 56 materials. Glass fiber is used as a reinforcing material. Through the interface between glass fiber and PA5T / 56 matrix, it transfers load, disperses stress, and improves the rigidity of the material. In addition, the thermal stability of the composite material can be improved by adding antioxidants. The anti-static and flame-retardant PA5T / 56 material of the present invention has balanced rigidity, antistatic and flame retardant properties, and can be used in electronic component products that require high strength, antistatic and flame retardancy.

[0038] Finally, it should be noted that the terms "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0040] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An anti-static flame retardant PA5T / 56 composite material, characterized in that: The composite material includes the following components by mass percentage: 45%-60% PA5T / 56 resin, 20%-40% glass fiber, 10%-15% silane-modified nano-carbon black, 5%-10% stearic acid-modified nano-calcium carbonate and 0.5%-2% antioxidant.

2. The anti-static flame retardant PA5T / 56 composite material according to claim 1, characterized in that: The glass fiber is surface-treated chopped glass fiber.

3. The anti-static flame retardant PA5T / 56 composite material according to claim 1, characterized in that: The preparation method of the silane-modified nano-carbon black comprises: placing nano-carbon black in isopropyl alcohol and ultrasonically dispersing the nano-carbon black to obtain a nano-carbon black / isopropyl alcohol suspension; dissolving a silane coupling agent in anhydrous ethanol and ultrasonically dispersing the nano-carbon black / isopropyl alcohol suspension to obtain a silane coupling agent / ethanol mixed solution; placing the nano-carbon black / isopropyl alcohol suspension and the silane coupling agent / ethanol mixed solution in a three-necked flask and stirring at 90-100° C. for 4-6 hours to obtain a reaction solution; and filtering, washing, and drying the reaction solution to obtain the silane-modified nano-carbon black.

4. The anti-static flame retardant PA5T / 56 composite material according to claim 3, characterized in that: The volume ratio of the silane coupling agent to the anhydrous ethanol is 1:100-2:100; the added amount of the silane coupling agent is 10-20% of the mass of the nano carbon black.

5. The anti-static flame retardant PA5T / 56 composite material according to claim 1, characterized in that: The preparation method of stearic acid-modified nano-calcium carbonate comprises the following steps: placing nano-calcium carbonate in anhydrous ethanol and ultrasonically dispersing the nano-calcium carbonate to obtain a nano-calcium carbonate / ethanol suspension; ultrasonically dispersing stearic acid and anhydrous ethanol at a volume ratio of 1:100-5:100 at 45-50° C. and fully dissolving the stearic acid / ethanol solution to obtain a stearic acid / ethanol solution; placing the nano-calcium carbonate / ethanol suspension and the stearic acid / ethanol solution in a three-necked flask and stirring the mixture at 60-80° C. for 1-2 hours to obtain a reaction solution; and filtering, washing, drying, and grinding the reaction solution to obtain the stearic acid-modified nano-calcium carbonate.

6. The anti-static flame retardant PA5T / 56 composite material according to claim 5, characterized in that: The added amount of the stearic acid is 2-5% of the mass of the nano-calcium carbonate.

7. The anti-static flame retardant PA5T / 56 composite material according to claim 1, characterized in that: The antioxidant is N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine.

8. A method for preparing an anti-static flame-retardant PA5T / 56 composite material, characterized in that: The preparation method comprises: Preparation of silane-modified nanocarbon black; Preparation of stearic acid modified nano calcium carbonate; Weighing the raw material components of the composite material, the raw material components include: A5T / 56 resin 45%-60%, glass fiber 20%-40%, silane modified nano carbon black 10%-15%, stearic acid modified nano calcium carbonate 5%-10% and antioxidant 0.5%-2%; Premixing the A5T / 56 resin, the silane-modified nano-carbon black, the stearic acid-modified nano-calcium carbonate, and the antioxidant to obtain an initial mixture; The initial mixture is added from a main feeding hopper and conveyed into the screw cavity of a twin-screw extruder. The glass fiber is added from a side feeding hopper and conveyed into the screw cavity of the twin-screw extruder. After heating, melting, extrusion and granulation, an anti-static and flame-retardant PA5T / 56 composite material is obtained.

9. The method for preparing the anti-static flame-retardant PA5T / 56 composite material according to claim 8, characterized in that: The preparation of silane-modified nano-carbon black specifically includes: Weigh nano carbon black and 10-20% by mass of a silane coupling agent respectively; placing the nano carbon black in isopropyl alcohol and performing ultrasonic dispersion to obtain a nano carbon black / isopropyl alcohol suspension; Ultrasonic dispersion of a silane coupling agent and anhydrous ethanol in a volume ratio of 1:100-2:100 is performed to obtain a silane coupling agent / ethanol mixed solution; placing the nano carbon black / isopropanol suspension and the silane coupling agent / ethanol mixed solution in a three-necked flask, and stirring at 90-100° C. for 4-6 hours to obtain a reaction solution; Filtering and washing the reaction solution to obtain a filter cake; The filter cake was placed in a vacuum drying oven at 100° C. for drying to obtain silane-modified nano-carbon black.

10. The method for preparing the anti-static flame-retardant PA5T / 56 composite material according to claim 8, characterized in that: The preparation of stearic acid modified nano calcium carbonate specifically includes: Weigh nano calcium carbonate and 2-5% stearic acid respectively; placing the nano-calcium carbonate in anhydrous ethanol and performing ultrasonic dispersion to obtain a nano-calcium carbonate / ethanol suspension; Ultrasonic dispersion of stearic acid and anhydrous ethanol at a volume ratio of 1:100-5:100 at 45-50° C. to fully dissolve to obtain a stearic acid / ethanol solution; The nano-calcium carbonate / ethanol suspension and the stearic acid / ethanol solution are placed in a three-necked flask and stirred at 60-80° C. for 1-2 hours to obtain a reaction solution; Filtering and washing the reaction solution to obtain a filter cake; The filter cake is placed in a vacuum drying oven at 100° C. for drying, and then ground to obtain stearic acid-modified nano-calcium carbonate.

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