Green and environment-friendly electric insulation repair material and preparation method thereof

Abstract

The invention relates to a green and environment-friendly electric insulation repairing material and a preparation method thereof, and belongs to the technical field of insulating materials. A formula of the green and environment-friendly electric insulation repair material comprises the following components in parts by weight: 30-50 parts of cardanol-based phenolic resin, 10-20 parts of modified filler, 1-2 parts of liquid nitrile rubber, 20-30 parts of ethanol and 10-15 parts of cashew nut shell oil modified amine. The material formula and the preparation process provided by the invention have the characteristics of being green and environment-friendly, and the electrical insulation repair material prepared by the invention has good electrical insulation and mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of insulating materials and relates to a green and environmentally friendly electrical insulating repair material and a preparation method thereof. Background Art

[0002] Traditional electrical insulation repair materials suffer from environmental deficiencies, low curing efficiency, and performance deficiencies. For example, heat-curing epoxy resin systems rely on benzene-based solvents, releasing volatile organic compounds (VOCs) during the curing process, which poses a health risk to operators. Heat curing takes hours or even days, making it difficult to meet the demands of rapid field repairs. UV-curable resins are prone to cracking, exhibit unstable electrical properties, and modified fillers exhibit poor dispersion, resulting in insufficient insulation strength. Therefore, the development of green and environmentally friendly electrical insulation repair materials is urgently needed. Summary of the Invention

[0003] The purpose of the present invention is to provide a green and environmentally friendly electrical insulation repair material and a preparation method thereof, which has good electrical insulation properties and is green and environmentally friendly.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A green and environmentally friendly electrical insulation repair material, the green and environmentally friendly electrical insulation repair material has the following formula: calculated by weight, 30-50 parts of cardanol-based phenolic resin, 10-20 parts of modified filler, 1-2 parts of liquid nitrile rubber, 20-30 parts of ethanol, and 10-15 parts of cashew nut shell oil-modified amine. Wherein, the preparation method of the modified filler is as follows: S1-1: 10-20 parts by weight of mica powder and 5-10 parts by weight of silicon dioxide were mixed, added to a ball mill, and ball milled for 1-2 hours to obtain a mixture A; S1-2: Add mixture A to 100 parts by weight of a 50% ethanol solution, ultrasonicate at 50-60°C for 10-20 min, then add 2-3 parts by weight of γ-aminopropyltriethoxysilane, maintain the temperature and stir at a speed of 200-300 rpm for 1-2 h, wash with anhydrous ethanol, and then dry in a vacuum drying oven for 12 h to obtain the modified filler.

[0005] As a preferred technical solution of the present invention, the preparation method of the cardanol-based phenolic resin is as follows: Cardanol and phenol are mixed in a molar ratio of 4:3, zinc acetate is added, and the mixture is stirred at a speed of 350-450 r / min at 40-50 ° C for 40-60 min. Then, formaldehyde solution is added dropwise. After the addition is completed, the temperature is raised to 85-95 ° C, and the mixture is stirred at a speed of 150-250 r / min for 4-6 min. The mixture is placed at 100 ° C and vacuum dried for 12 h to obtain the cardanol-based phenolic resin.

[0006] As a preferred technical solution of the present invention, the ball milling speed in S1-1 is 100~180 rpm.

[0007] As a preferred technical solution of the present invention, the addition amount of γ-aminopropyltriethoxysilane in S1-2 is 5-8% of the mass of mixture A.

[0008] As a preferred technical solution of the present invention, the added amount of zinc acetate is 2-3% of the mass of cardanol.

[0009] As a preferred technical solution of the present invention, the cardanol and phenol are total phenols, and the molar ratio of formaldehyde to total phenol is 1:1.

[0010] As a preferred technical solution of the present invention, the dropwise addition rate of the formaldehyde solution is 2-3 mL / min.

[0011] A method for preparing a green and environmentally friendly electrical insulation repair material, the specific steps of the preparation method are as follows: S8-1: Add cardanol-based phenolic resin to ethanol according to the formula ratio and stir at 45-55°C for 30-60 minutes; S8-2: Add the modified filler and disperse at 1000-1100 rpm for 30-60 min. Then, add liquid nitrile rubber, raise the temperature to 55-65°C, and homogenize for another 20-30 min. S8-3: Add cashew nut shell liquid modified amine, mix at a speed of 300-400 rpm for 10-20 min, and then perform vacuum degassing for 20-30 min at a vacuum degree of 0.09 MPa and a temperature of 50°C to obtain the green and environmentally friendly electrical insulation repair material.

[0012] As a preferred technical solution of the present invention, the stirring speed in S8-1 is 300~500 rpm.

[0013] As a preferred technical solution of the present invention, the homogenization speed in S8-2 is 500~600 rpm and the pressure is 15~20 MPa.

[0014] The cardanol-based phenolic resin prepared by this invention achieves improved performance and environmental friendliness through the synergistic compounding of cardanol and phenol and process innovation. The long-chain alkyl group of cardanol not only imparts flexibility to the resin, but its hydrophobic properties significantly increase the surface contact angle of the material, effectively blocking conductive pathways and thus improving electrical insulation performance. Simultaneously, the rigid benzene ring structure of phenol enhances heat resistance and crosslink density control. When the two are mixed in a specific ratio, the tensile strength and elongation at break of the material are increased, forming a rigid and flexible insulating framework. Using zinc acetate instead of traditional strong acid catalysts not only promotes the efficient copolymerization of cardanol and phenol, building a uniform network structure, but also reduces the incidence of formaldehyde self-polymerization side reactions, lowers free formaldehyde content, and significantly reduces the chemical oxygen demand (COD) in wastewater. This catalytic system also lowers the curing temperature, making it more energy-efficient than traditional processes. Furthermore, by replacing some petroleum-based raw materials with cardanol, the resin's bio-based carbon content is increased, significantly reducing CO2 emissions during the production process, achieving both excellent insulation durability and environmental friendliness.

[0015] In addition, the present invention significantly improves the comprehensive performance of electrical insulation repair materials through the composite synergy of mica powder and silica and surface silanization modification. The layered structure of mica powder gives the material excellent insulation barrier properties, and the spherical particles of silica enhance rigidity and optimize the heat conduction path. After ball milling, the two particles are refined to form a tightly packed structure, which improves the volume resistivity of the material. γ-Aminopropyltriethoxysilane chemically bonds with the hydroxyl group on the filler surface under the assistance of ultrasound at 55°C, improving the interfacial shear strength, effectively transferring stress, and improving the tensile strength and impact toughness of the material; at the same time, the modified filler increases the hydrophobicity of the material, ensuring insulation stability in a hot and humid environment.

[0016] Liquid nitrile rubber forms hydrogen bonds with the hydroxymethyl groups of phenolic resin through the cyano groups in its molecular chain, enhancing the material's impact strength while simultaneously increasing its elongation at break and significantly reducing its brittleness. Furthermore, its low dosage enhances toughness while maintaining the system's insulation properties. High-pressure homogenization achieves nanoscale dispersion, ensuring isotropic mechanical properties.

[0017] Ethanol, as a green solvent, replaces the traditional toluene / acetone system in the formula. It leaves no toxic residue after volatilization and has extremely low VOC emissions. The vacuum degassing process controls the solvent residue to less than 2%. The material has a high density after curing, avoiding pore defects caused by solvents and ensuring insulation reliability.

[0018] Cashew nut shell liquid (CNSL)-modified amines, as bio-based curing agents, cure at lower temperatures through a polycondensation reaction between the long-chain fatty amines in CNSL and the hydroxymethyl groups of phenolic resins, achieving energy savings compared to traditional systems. Furthermore, the flexible ether bonds in the CNSL-modified amine molecular chain create a synergistic effect with the rigid benzene rings, raising the material's heat deformation temperature while maintaining excellent electrical insulation properties. CNSL-modified amines, as a further processed product of CNSL, can significantly reduce CO2 emissions compared to traditional curing agents, significantly improving the material's environmental friendliness.

[0019] Beneficial effects of the present invention: (1) The present invention prepares a bio-based resin with both high insulation and environmental friendliness through the coordinated design of the molar ratio of cardanol and phenol and the zinc acetate catalyst system. The long-chain alkyl group of cardanol gives the material hydrophobicity, significantly improving its moisture resistance and insulation performance. At the same time, the rigid benzene ring structure of phenol increases the heat deformation temperature, tensile strength and elongation at break; the zinc acetate catalyst reduces the curing temperature, energy consumption, and reduces the free formaldehyde content and wastewater COD.

[0020] (2) A composite filler of mica powder and silica was used, which was refined by ball milling and surface modified with γ-aminopropyltriethoxysilane to construct a high-insulation, high-toughness reinforcement system. The layered structure of mica formed a conductive path barrier layer, and the spherical particles of silica optimized the heat conduction path, significantly improving the volume resistivity of the material. Silanization modification enhanced the interfacial bonding strength through chemical bonding, thereby increasing the tensile strength and impact toughness, while also increasing the hydrophobic angle, ensuring insulation stability in hot and humid environments.

[0021] (3) Liquid nitrile rubber achieves nano-scale dispersion through the action of cyanide and hydroxymethyl hydrogen bonds, which improves the impact strength and elongation at break at low dosage; ethanol as a green solvent significantly reduces VOC emissions; cashew nut shell oil modified amine as a bio-based curing agent completes curing at a lower temperature, and the synergistic effect of its flexible ether bond and rigid benzene ring increases the heat deformation temperature, while effectively reducing CO2 emissions. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0023] Example 1 A green and environmentally friendly electrical insulation repair material, the green and environmentally friendly electrical insulation repair material formula 1 is as follows, calculated by weight, 450 parts of cardanol-based phenolic resin, 15 parts of modified filler, 1.5 parts of liquid nitrile rubber, 25 parts of ethanol, 12 parts of cashew shell oil modified amine, Wherein, the preparation method of the modified filler is as follows: S1-1: 15 parts by weight of mica powder and 8 parts by weight of silicon dioxide were mixed, added to a ball mill, and milled for 1.5 hours at a ball mill speed of 150 rpm to obtain a mixture A; S1-2: Add mixture A to 100 parts by weight of a 50% ethanol solution, ultrasonicate at 55°C for 15 min, then add 2.5 parts by weight of γ-aminopropyltriethoxysilane (6% by mass of mixture A), maintain the temperature and stir at 250 rpm for 1.5 h, wash with anhydrous ethanol, and then dry in a vacuum drying oven for 12 h to obtain the modified filler.

[0024] The preparation method of the cardanol-based phenolic resin is as follows: Cardanol and phenol are mixed in a molar ratio of 4:3, zinc acetate (2.5% by mass of cardanol) is added, and the mixture is stirred at 400 r / min at 45°C for 50 min. Subsequently, formaldehyde solution is added dropwise at a rate of 2.5 mL / min, wherein cardanol and phenol are total phenols, and the molar ratio of formaldehyde to total phenols is 1:1. After the addition is completed, the temperature is raised to 90°C, stirred at 200 r / min for 5 min, and placed at 100°C for vacuum drying for 12 h to obtain the cardanol-based phenolic resin.

[0025] A method for preparing a green and environmentally friendly electrical insulation repair material, the specific steps of the preparation method are as follows: S8-1: Add cardanol-based phenolic resin to ethanol according to the ratio of formula 1, stir at 50°C for 45 minutes, and stir at 400 rpm; S8-2: Add the modified filler and disperse at 1050 rpm for 45 min. Then, add liquid nitrile rubber, raise the temperature to 60°C, and homogenize for another 25 min at a speed of 550 rpm and a pressure of 17 MPa. S8-3: Add cashew nut shell liquid modified amine, mix at 350 rpm for 15 minutes, and then perform vacuum degassing for 25 minutes at a vacuum degree of 0.09 MPa and a temperature of 50° C. to obtain the green and environmentally friendly electrical insulation repair material.

[0026] Example 2 A green and environmentally friendly electrical insulation repair material, the green and environmentally friendly electrical insulation repair material formula 2 is as follows, calculated by weight, 30 parts of cardanol-based phenolic resin, 10 parts of modified filler, 1 part of liquid nitrile rubber, 20 parts of ethanol, 10 parts of cashew shell oil modified amine, Wherein, the preparation method of the modified filler is as follows: S1-1: 10 parts by weight of mica powder and 5 parts by weight of silicon dioxide were mixed, added to a ball mill, and milled for 1 h at a ball mill speed of 100 rpm to obtain a mixture A; S1-2: Add mixture A to 100 parts by weight of a 50% ethanol solution, ultrasonicate at 50°C for 10 min, then add 2 parts by weight of 5% γ-aminopropyltriethoxysilane of mixture A, maintain the temperature and stir at 200 rpm for 1 h, wash with anhydrous ethanol, and then dry in a vacuum drying oven for 12 h to obtain the modified filler.

[0027] The preparation method of the cardanol-based phenolic resin is as follows: Cardanol and phenol are mixed in a molar ratio of 4:3, zinc acetate (2% by mass of cardanol) is added, and the mixture is stirred at 350 r / min at 40°C for 40 min. Subsequently, formaldehyde solution is added dropwise at a rate of 2 mL / min, wherein cardanol and phenol are total phenols, and the molar ratio of formaldehyde to total phenols is 1:1. After the addition is completed, the temperature is raised to 85°C, the mixture is stirred at 150 r / min for 4 min, and the mixture is placed at 100°C for vacuum drying for 12 h to obtain the cardanol-based phenolic resin.

[0028] A method for preparing a green and environmentally friendly electrical insulation repair material, the specific steps of the preparation method are as follows: S8-1: Add cardanol-based phenolic resin to ethanol according to the ratio of formula 2, stir at 45°C for 30 minutes, and stir at 300 rpm; S8-2: Add the modified filler and disperse at 1000 rpm for 30 min. Then, add liquid nitrile rubber, raise the temperature to 55°C, and homogenize for another 20 min at a homogenization speed of 500 rpm and a pressure of 15 MPa. S8-3: Add cashew nut shell liquid modified amine, mix at 300 rpm for 10 min, and then perform vacuum degassing for 20 min at a vacuum degree of 0.09 MPa and a temperature of 50° C. to obtain the green and environmentally friendly electrical insulation repair material.

[0029] Example 3 A green and environmentally friendly electrical insulation repair material, the green and environmentally friendly electrical insulation repair material formula 3 is as follows, calculated by weight, 50 parts of cardanol-based phenolic resin, 20 parts of modified filler, 2 parts of liquid nitrile rubber, 30 parts of ethanol, 15 parts of cashew shell oil modified amine, Wherein, the preparation method of the modified filler is as follows: S1-1: 20 parts by weight of mica powder and 10 parts by weight of silicon dioxide were mixed, added to a ball mill, and milled for 2 h at a ball mill speed of 180 rpm to obtain a mixture A; S1-2: Add mixture A to 100 parts by weight of a 50% ethanol solution, ultrasonicate at 60°C for 20 min, then add 3 parts by weight of 8% by mass of γ-aminopropyltriethoxysilane, maintain the temperature and stir at 300 rpm for 2 h, wash with anhydrous ethanol, and then dry in a vacuum drying oven for 12 h to obtain the modified filler.

[0030] The preparation method of the cardanol-based phenolic resin is as follows: Cardanol and phenol were mixed in a molar ratio of 4:3, zinc acetate (3% by mass of cardanol) was added, and the mixture was stirred at 450 r / min at 50°C for 60 min. Subsequently, formaldehyde solution was added dropwise at a rate of 3 mL / min. Cardanol and phenol were total phenols, and the molar ratio of formaldehyde to total phenols was 1:1. After the addition was completed, the temperature was raised to 95°C, the mixture was stirred at 250 r / min for 6 min, and the mixture was placed at 100°C for vacuum drying for 12 h to obtain the cardanol-based phenolic resin.

[0031] A method for preparing a green and environmentally friendly electrical insulation repair material, the specific steps of the preparation method are as follows: S8-1: Add cardanol-based phenolic resin to ethanol according to the ratio of formula 3, stir at 55°C for 60 minutes, and stir at 500 rpm; S8-2: Add the modified filler and disperse at 1100 rpm for 60 min. Then, add liquid nitrile rubber, raise the temperature to 65°C, and homogenize for another 30 min at 600 rpm and 20 MPa. S8-3: Add cashew nut shell oil modified amine, mix at 400 rpm for 20 min, and then perform vacuum degassing for 30 min at a vacuum degree of 0.09 MPa and a temperature of 50° C. to obtain the green and environmentally friendly electrical insulation repair material.

[0032] Comparative Example 1 No modified filler was added, and the remaining steps were the same as in Example 1.

[0033] Comparative Example 2 No mica powder was added during the preparation of the modified filler, and the remaining steps were the same as those in Example 1.

[0034] Comparative Example 3 No mica powder was added during the preparation of the modified filler, and the remaining steps were the same as those in Example 1.

[0035] Comparative Example 4 γ-aminopropyltriethoxysilane was not added during the preparation of the modified filler, and the remaining steps were the same as those in Example 1.

[0036] Comparative Example 5 The traditional phenolic resin replaced the cardanol-based phenolic resin, and the remaining steps were consistent with those in Example 1.

[0037] Volume resistivity test According to GB / T 1410-2006, the volume resistivity of the green and environmentally friendly electrical insulation repair materials prepared in the examples and comparative examples after complete curing was tested using a high resistance meter at a voltage of 100 V. The experimental results are summarized in the following table.

[0038] It can be seen from the experimental data of the embodiments and comparative examples that the green and environmentally friendly electrical insulation repair material prepared by the method of the present invention has good electrical insulation properties.

[0039] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A green and environmentally friendly electrical insulation repair material, characterized in that: The green and environmentally friendly electrical insulation repair material is formulated as follows: calculated by weight, 30-50 parts of cardanol-based phenolic resin, 10-20 parts of modified filler, 1-2 parts of liquid nitrile rubber, 20-30 parts of ethanol, and 10-15 parts of cashew nut shell oil-modified amine. Wherein, the preparation method of the modified filler is as follows: S1-1: 10-20 parts by weight of mica powder and 5-10 parts by weight of silicon dioxide were mixed, added to a ball mill, and ball milled for 1-2 hours to obtain a mixture A; S1-2: Add mixture A to 100 parts by weight of a 50% ethanol solution, ultrasonicate at 50-60°C for 10-20 min, then add 2-3 parts by weight of γ-aminopropyltriethoxysilane, maintain the temperature and stir at a speed of 200-300 rpm for 1-2 h, wash with anhydrous ethanol, and then dry in a vacuum drying oven for 12 h to obtain the modified filler.

2. The green and environmentally friendly electrical insulation repair material according to claim 1, characterized in that: The preparation method of the cardanol-based phenolic resin is as follows: Cardanol and phenol are mixed in a molar ratio of 4:3, zinc acetate is added, and the mixture is stirred at a speed of 350-450 r / min at 40-50 ° C for 40-60 min. Then, formaldehyde solution is added dropwise. After the addition is completed, the temperature is raised to 85-95 ° C, and the mixture is stirred at a speed of 150-250 r / min for 4-6 min. The mixture is placed at 100 ° C and vacuum dried for 12 h to obtain the cardanol-based phenolic resin.

3. The green and environmentally friendly electrical insulation repair material according to claim 1, characterized in that: The ball milling speed in S1-1 is 100~180 rpm.

4. The green and environmentally friendly electrical insulation repair material according to claim 1, characterized in that: The amount of γ-aminopropyltriethoxysilane added in S1-2 is 5-8% by mass of the mixture A.

5. The green and environmentally friendly electrical insulation repair material according to claim 2, characterized in that: The added amount of zinc acetate is 2-3% of the mass of cardanol.

6. The green and environmentally friendly electrical insulation repair material according to claim 2, characterized in that: The cardanol and phenol are total phenols, and the molar ratio of formaldehyde to total phenols is 1:

1.

7. The green and environmentally friendly electrical insulation repair material according to claim 2, characterized in that: The dropwise addition rate of the formaldehyde solution is 2-3 mL / min.

8. A method for preparing the green and environmentally friendly electrical insulation repair material according to any one of claims 1 to 7, characterized in that: The specific steps of the preparation method are as follows: S8-1: Add cardanol-based phenolic resin to ethanol according to the formula ratio and stir at 45-55°C for 30-60 minutes; S8-2: Add the modified filler and disperse at 1000-1100 rpm for 30-60 min. Then, add liquid nitrile rubber, raise the temperature to 55-65°C, and homogenize for another 20-30 min. S8-3: Add cashew nut shell liquid modified amine, mix at a speed of 300-400 rpm for 10-20 min, and then perform vacuum degassing for 20-30 min at a vacuum degree of 0.09 MPa and a temperature of 50°C to obtain the green and environmentally friendly electrical insulation repair material.

9. The method for preparing a green and environmentally friendly electrical insulation repair material according to claim 8, characterized in that: The stirring speed in S8-1 is 300-500 rpm.

10. The method for preparing a green and environmentally friendly electrical insulation repair material according to claim 8, characterized in that: In the S8-2, the homogenization speed is 500-600 rpm and the pressure is 15-20 MPa.

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