Research On The Preparation Technology Of Epoxy Resin Anticorrosion Coating On Non-working Surface Of Aluminum Cathode For Zinc Electrowinnin

As the aluminum cathode plate is subjected to the erosion of acid mist,moisture and high concentration of salt media for a long time,the oxidation layer on the surface is easily corroded by acid and alkali,resulting in the corrosion failure of the cathode plate,so it is very necessary to do anti-corrosion treatment on the surface of the aluminum cathode plate,of which coating treatment is regarded as the easiest and efficient way to treat.However,the coating often peels and blisters under harsh conditions,resulting in ineffective protection of the aluminum cathode plate.Therefore,it is necessary to optimize the coating formulation,extend the physical barrier path of the coating and increase the degree of polymerization of the coating to improve the corrosion resistance of the coating and retard the erosion of the corrosive medium on the aluminum cathode plate.In this paper,we choose E44 and E51epoxy resins with different content and mesh of glass scales and silica micropowder to form a"labyrinth effect"and a high polymerization mesh structure with different amine curing agents to design an anti-corrosion coating with fast drying speed,strong adhesion and impact resistance.By testing the corrosion resistance and mechanical properties of the designed coating,the following conclusions were obtained:1、The AC impedance and physical properties of epoxy resin E44 and E51,epoxy phenolic resin F44,epoxy vinyl resin 907 and other series of resins were tested,and it was determined that the best adhesion was 12.09 MPa for E44（main agent:T31=2:1）,E51 had better corrosion resistance,and the impedance value of E51 could reach 10¹⁰Ω·cm²at the early stage of immersion,and epoxy resin The coating has excellent corrosion resistance when the ratio of E44 and epoxy resin E51 is 1:2,and the impedance value can exceed 10⁸Ω·cm²at the early stage of immersion.2、The penetration model analysis of the filler composed of glass scale and silica micropowder,in the glass scale of 20wt%,mesh number 160,silica micropowder of 15wt%,mesh number 1250,the coating has excellent anti-corrosion properties,in the early stage of immersion,can reach nearly 10¹²Ω·cm²,and in a long frequency range of the phase angle maintained at more than 80°,when using Si C36 mesh The adhesion can reach up to 18.25MPa when treated with a combination of sandblasting and chroming.3、When DSM SN833 polyester resin is used to toughen the coating,when its content is4%,the flexibility of the coating is 10mm,the impact strength is 30cm,and the adhesion is13.32MPa（curing agent 1635）.Adhesion promoter can improve the adhesion of the coating,additive 4512 has good corrosion resistance,additive 2063 has the best adhesion and can reach 12.85MPa,when the ratio of additive 2063 and additive 4512 is 2:1,the adhesion can reach 14.40MPa and has the best corrosion resistance,add 0.2%defoamer PB2720 or do vacuum defoaming treatment on the coating Adding 0.2%defoamer PB2720 or doing vacuum defoaming on the coating can improve the adhesion of the coating and the substrate.4、The selection of DSM SN833 polyester resin on the coating toughness study,when its content of 4%wt,the coating flexibility of 10mm,impact strength of 30cm,adhesion of13.32MPa.at the same time,adhesion promoter to improve the adhesion of the coating has a greater help,additive 4512 good corrosion resistance,impedance value of the largest,close to1010Ω-cm2 additive 2063 adhesion force is the best,can reach 12.85MPa,additive 2063 and additive 4512 ratio of 2:1 combination,adhesion force can reach 14.40MPa,add 0.2wt%defoamer PB2720 or do vacuum defoaming treatment on the coating,can improve the bonding force of the coating and the substrate 3-4Mpa.