Preparation And Study Of Two-component Waterborne Epoxy Primer / Polyurethane Topcoat Coatings For Construction Machinery

In this paper,the two-component waterborne epoxy primer/polyurethane topcoat anticorr osive coatings for construction machinery were prepared.The composite coating effectively i mproved the overall performance of the coatings such as corrosion resistance,weather resistan ce and chemical resistance.The content of the paper is mainly divided into two parts:1?Using epoxy resin as the film-forming substance,the effects of the type matching of e poxy emulsion and amine curing agent,the type and amount of anti-rust pigment,the volume concentration of pigment and filler(PVC),the amount of anti-rust pigment and the amount of curing agent on gloss,hardness,adhesion,impact strength,water resistance,acid resistance,al kali resistance and salt spray resistance of two-component waterborne epoxy anticorrosive pri mer were discussed respectively.Through Fourier Infrared Spectroscopy(FTIR),Scanning El ectron Microscope(SEM),Electrochemical Impedance Spectroscopy(EIS)and other test met hods,the group structure of the epoxy resin,the surface morphology of the epoxy coating and the corrosion mechanism of the coating were characterized and analyzed.The results showed t hat when the selected epoxy emulsion was Banco2092,the amine curing agent was Banco920,the anti-rust pigment was ZMP-1,PVC was 30%,the amount of anti-rust pigment was 10%,a nd the n(epoxy)/n(active hydrogen)of curing agent was 1.0;the performances of epoxy prim er were the best.The undercoat could be dried in 17 minutes,the pencil hardness of the paint f ilm reached H,the adhesion reached 0 grade,and the impact strength exceeded 50kg·cm,the water resistance exceeded 2000 h,the acid resistance and alkali resistance reached 48 h,and the neutral salt spray resistance reached 720 h.2?With polyurethane as the film-forming material,the effect of the types of hydroxy acr ylate dispersion and isocyanate curing agent,the amount of curing agent,the type of dispersan t and the type of titanium dioxide on the gloss,hardness,adhesion,impact strength,water resi stance,acid resistance,alkali resistance and salt spray resistance of the two-component waterb orne polyurethane topcoat were discussed separately.The group structure of polyurethane and the surface morphology of polyurethane topcoat were characterized and analyzed by Fourier I nfrared Spectrometer(FTIR)and Scanning Electron Microscope(SEM).The results showed t hat when the selected hydroxy acrylate dispersion was Antkote 2042,the isocyanate curing ag ent Aquolin269,the ratio of n(-NCO)/n(-OH)of isocyanate curing agent 1.3,the dispersant T EGO760 w,and the titanium dioxide model R998,the prepared polyurethane topcoat had the b est overall performances.The gloss reached 85-90,the pencil hardness reached H,the adhesio n was 0 grade,the impact strength exceeded 50kg·cm,the water resistance reached 120 h,the a cid resistance reached 96 h,and the alkali resistance reached 48 h.By combining the two-comp onent waterborne polyurethane topcoat and the two-component waterborne epoxy primer,an e poxy primer/polyurethane topcoat anti-corrosion coating was prepared.The gloss of the coatin g reached 85-90,hardness reached H,adhesion was 0 grade,impact strength exceeded 50cm·k g,water resistance exceeded 2000 h,acid resistance reached 168 h,alkali resistance reached 96 h,and salt spray resistance exceeded 1000 h.The comprehensive performance of the composit e coatings meets the performance requirements of the engineering machinery coating system i n the industry standard HGT4339-2012.