CN-118791949-B - Preparation method of conductive self-repairing coating on surface of aluminum shielding tape

Abstract

The invention discloses a preparation method of a conductive self-repairing coating on the surface of an aluminum shielding tape, which comprises the steps of firstly obtaining the clean surface of the aluminum shielding tape by an in-situ reduction/etching pretreatment method based on an aluminum salt/fluoride salt compound solution, secondly preparing a conductive/repairing double-effect reinforcing agent, introducing polyether amine, diisocyanate, a multi-activity amine compound, terephthalaldehyde and aniline into a conductive/self-repairing coating synthesized by the polyether amine, diisocyanate, and finally adjusting the solid content of the coating to spray on the clean surface of the aluminum shielding tape to obtain the conductive self-repairing coating.

Inventors

• TANG YUFEI
• JIANG JUNYI
• XING GUOXIN
• TANG CHEN
• LIU ZHAOWEI
• ZHONG PENGJIAO
• GUO JIANXIAO
• WANG HAO

Assignees

• 西安理工大学

Dates

Publication Date

20260508

Application Date

20240802

Claims (6)

1. 1. The preparation method of the conductive self-repairing coating on the surface of the aluminum shielding tape is characterized by comprising the following steps of: Step 1, aluminum material in-situ reduction/etching pretreatment: Adding a mixed solution of aluminum fluoride and sodium fluoride into a container, regulating the pH value of the mixed solution, immersing an aluminum shielding belt serving as a cathode and a graphite sheet serving as an anode in the mixed solution to keep a proper distance, regulating the temperature of the mixed solution and the current density of an external power supply, and carrying out reduction etching for a certain time under the conditions to obtain a clean aluminum shielding belt subjected to in-situ reduction/etching pretreatment; step 2, preparing a conductive/repair double-effect reinforcing agent: Adding a suspension formed by uniformly dispersing a carboxyl carbon nano tube and dimethylacetamide into a three-necked flask, introducing N 2 gas, continuously stirring, then dropwise adding excessive isocyanate, dibutyltin dilaurate and a proper amount of dimethylacetamide into the three-necked flask, mixing to obtain a mixed solution, stirring the mixed solution at 60-80 ℃ for reaction for 6-10 hours after the dropwise adding is completed, and filtering and washing to obtain the conductive/repair double-effect reinforcing agent; step 3, preparing a conductive/self-repairing coating: Weighing a conductive/repair double-effect reinforcing agent, diisocyanate, polyether amine and dimethylacetamide, carrying out prepolymerization reaction for a certain time under the atmosphere of N 2 , then dropwise adding a compound solvent consisting of aniline, adipic acid dihydrazide, diamine compound, terephthalaldehyde and dimethylacetamide, carrying out continuous polymerization reaction for a certain time under the atmosphere of N 2 , and finally adding a defoaming agent and a leveling agent to obtain the conductive/self-repair coating; Step 4, preparing a conductive/self-repairing coating on the surface of the aluminum shielding tape: firstly, adding a proper amount of dimethylacetamide solvent into the conductive/self-repairing coating obtained in the step 3 to adjust the solid content of a coating system, then atomizing and spraying the coating on the surface of the aluminum shielding belt obtained in the step 1, and finally drying to finish the preparation of the conductive self-repairing coating on the surface of the aluminum shielding belt.
2. 2. The method for preparing the conductive self-repairing coating on the surface of the aluminum shielding tape according to claim 1, wherein in the step 1, the mass fraction of aluminum fluoride to sodium fluoride is 5-12%, the mass ratio of aluminum fluoride to sodium fluoride is 2:0.5-1.5, the pH range is 4.5-6, the temperature of the mixed solution is regulated and controlled to be 30-60 ℃, the current density of an external power supply is 5-25 mA/cm 2 , and the reduction etching reaction time is 5-20 min.
3. 3. The method for preparing the conductive self-repairing coating on the surface of the aluminum shielding tape according to claim 1, wherein in the step 2, the addition amount of carboxyl carbon nano tubes is 0.5-1 g, dimethylacetamide is 100mL, isocyanate is hexamethylene diisocyanate, the addition amount of isocyanate is 6-12 g, and the addition amount of dibutyltin dilaurate is 0.1-0.2 g.
4. 4. The preparation method of the conductive self-repairing coating on the surface of the aluminum shielding tape according to claim 1 is characterized in that in the step 3, the conductive/repairing double-effect reinforcing agent is 1-5 parts by mass, the diisocyanate is 16-28 parts by mass, the polyether amine is 30-60 parts by mass, the total of the components of the pre-polymerization solvent is 200 parts by mass, the aniline in the compound solvent is 7-9 parts by mass, the adipic acid dihydrazide is 4-8 parts by mass, the diamine compound is 5-10 parts by mass, the terephthalaldehyde is 1-3 parts by mass, the dimethylacetamide is 30 parts by mass, the diisocyanate is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate and trimethyl hexamethylene diisocyanate, the diamine compound is one or more of isophorone diamine, diethyl toluene diamine, 2'- (ethylene dioxy) bis (ethylamine), 1, 6-hexamethylene diamine and 4,4' -dithiodiphenylamine, and the defoamer is added in an amount of 0.5-1.5 parts by mass.
5. 5. The method for preparing the conductive self-repairing coating on the surface of the aluminum shielding tape according to claim 1, wherein the pre-polymerization time in the step 3 is 1-6 hours, the pre-polymerization temperature is 25-60 ℃, the polymerization time is 0.5-2.5 hours, and the polymerization temperature is 60-80 ℃.
6. 6. The method for preparing the conductive self-repairing coating on the surface of the aluminum shielding tape according to claim 1, wherein the solid content of the coating system is adjusted to be 15-28% in the step 4.

Description

Preparation method of conductive self-repairing coating on surface of aluminum shielding tape Technical Field The invention belongs to the field of cable shielding tape protection, and particularly relates to a preparation method of a conductive self-repairing coating on the surface of an aluminum shielding tape. Background The shielding belt plays a vital role in the middle-low voltage cable structure, and can uniformly distribute the electric field in the cable and prevent the electric field concentration in the insulating layer, thereby reducing the risk of partial discharge. Meanwhile, the shielding belt can effectively shield external electromagnetic interference, prevent electromagnetic radiation inside the cable from interfering with external equipment and the environment, and ensure normal operation of the cable and peripheral equipment thereof. In addition, the shielding tape also increases the mechanical strength and structural stability of the cable, prevents the cable from being damaged by external force in the laying and using processes, and improves the durability and reliability of the cable. At present, common cable shielding tape materials include copper foil shielding tapes, aluminum foil shielding tapes, tin-plated copper shielding tapes, silver-plated copper shielding tapes and the like, wherein copper-based materials are widely used in cable shielding applications. The use of aluminum-based materials to replace copper in cable construction has been an unprecedented necessary measure. Although the cable shielding tape manufactured by aluminum can further meet the application requirement of light weight of cables, aluminum is an active metal, and can quickly form a compact oxide film with the thickness of 0.01-0.1 micrometer with oxygen in air. The film layer is amorphous and has a porous structure, and has the defects of poor insulativity, poor corrosion resistance and the like. The direct application of the aluminum shielding tape to the cable manufacture tends to cause the problems of heating, increasing contact resistance, reducing corrosion resistance and the like of the cable operation, and seriously affects the shielding performance and the service life of the cable. Therefore, changing the micro-nano structure and property of the surface of the aluminum shielding tape is a key factor for widening the market share of the aluminum shielding tape in the field of cable manufacturing. Chinese patent 'conductive anticorrosive coating technology of aluminum flow field plate' (application number: 201710470033.6, application publication number: CN 107425209A, publication date: 2017.12.01) is characterized in that pretreated aluminum is put into a graphene oxide aqueous solution containing tetrahydroxy aluminate ions for soaking, then the graphene oxide aqueous solution is soaked in sodium hypophosphite solution for treatment, and the aluminum flow field plate is washed by water and dried at normal temperature to obtain a conductive anticorrosive coating, so that the requirements of high corrosion resistance, high conductivity and low contact resistance of the aluminum flow field plate in a fuel cell environment are met. Although the dipping method has simple implementation, the scheme has obvious hidden environmental protection trouble, the dipping method is extremely easy to generate chemical waste liquid, the subsequent treatment flow is increased, and the process cost is increased. Secondly, the coating prepared by chemical impregnation of the aqueous solution is thinner, so that the wear resistance of the coating is greatly reduced, and the service life of the coating in practical application is reduced. The Chinese patent conductive anticorrosive paint, the preparation method and the application (application number: CN202210702259.5, application date: 2017.12.01) can effectively improve the corrosion resistance and the conductivity of the paint by matching the organic titanium polymer, the polyphenoloxy resin, the toughening agent, the conductive agent and the curing agent, but the filler addition amount of the conductive anticorrosive paint accounts for a relatively high proportion in the paint, so that the cost of the conductive anticorrosive paint is greatly improved, and the binding force of the coating is reduced. Chinese patent (202210506015. X, application date: 2022.05.11) reports a method for preparing a conductive anticorrosive coating on the surface of a magnesium alloy micro-arc oxidation layer, which is used for obtaining a PPy conductive material or a PPy/graphene conductive composite coating on the surface of the micro-arc oxidation layer, and the method has good corrosion resistance and conductivity, but the preparation steps are complex. In addition, spin coating can only prepare the coating on the surface of a simple planar sample, and cannot meet the conductive protection requirement of a complex structural member. Zhang Yan et al (Zhang Yan, kang Hailan, fang Qingg