Water-based epoxy coating system with crosslinking agent

Water-based epoxy coating system with crosslinking agent,In water-based epoxy coating system, anticorrosion pigment was the second largest after the resin on the coating performance influence factors, and with the development of waterborne coatings, looking for efficient, multifunctional and environmental friendly lead, chromium antirust pigment (red lead, zinc chrome yellow) effective alternative to become a problem to be solved are paint industry at home and abroad.

Non-toxic and environmentally friendly anticorrosive pigments on the market at present there are mainly phosphate series, the series of the second generation of modified phosphate (e.g., molybdate, ferrite, aluminate, etc.) and ion exchange type anticorrosive paint. All kinds of anticorrosion pigment anticorrosion mechanism exist similarities and differences.

Is common for phosphate series anticorrosive paint anticorrosion mechanism of the two views, a think: phosphate in water infiltration coating hydrolysis, the phosphate radical action to form the dynamic chelate with metal ions, protective film, to realize the protection of the metal substrate, also some people think that because the zinc phosphate and makings of the reaction of carboxyl and hydroxyl groups, generate complex, this complex can react with corrosion products, in the tight protective film is formed on the surface of the substrate, so as to protect metal substrate from corrosion.

Though the second generation of phosphate series as an anticorrosion pigment added new active component in the form, but this kind of compounds with the corrosion mechanism of phosphate, calcium and molybdenum, aluminum, the existence of the plasma can enhance the polarization resistance of the steel surface, reduce the critical current density required for the passivation and increase the stability of passive film, especially in the presence of chloride could improve corrosion resistance of substrate.

And anticorrosive mechanism of ion exchange type anticorrosion pigment is different, when corrosive electrolyte (H +) into the coating, which contact with the antirust paint, the latter will be the corrosive ions obtained on the surface of silica, and release the corresponding calcium ion and transferred to the metal substrate, when this process continues, the calcium ion layer is piling up in metal coating interface, thus plays a barrier for the protection and to enhance the adhesion of coating to the substrate.

This experiment chooses the molybdenum zinc phosphate, zinc phosphate, aluminum, zinc phosphate, aluminum phosphate, calcium ion exchange silica gel and blank experiment contrast, through the resistance to salt spray test, electrochemical impedance spectroscopy and EDAX analysis and characterization, after coating anticorrosion pigment proved protection mechanism and select the most suitable for the water system of the anticorrosion pigment.

The preparation of a two-component water-borne epoxy coating

The preparation of part A:

(1) adding deionized water and some additives, mixing around 15 min;

(2) adding anticorrosion pigment and filler and glass bead milling around 30 microns to fineness, remove the pulp;




Chinese name: Diethyl toluene diamine(DETDA)

Diethyltoluenediamine Raw material ：

TDA industrial, Sichuan production

Ethylene (Et) polymer grade, Shanghai production

TEA industrial imports

A reagent grade additives


(3) adding waterborne epoxy emulsion and some additives to remove the pulp, toss about 30 min.

Part B: water-based crosslinking agent.

Determination of anticorrosion pigment conductivity and form. Conductivity test: according to ISO 787-14 the General methods of test for pigments and extenders - Part 14: Determination of resistivity of aqueous extract, were determined. SEM test, scanning electron microscopy (SEM) tests of the anticorrosion pigment powder.

For waterborne epoxy coating containing different anticorrosion pigment according to the GB/T 1727-1992 general preparation method of the paint film to carry on the system board.

Waterborne epoxy coatings based on water as solvent or dispersion medium coating. Waterborne epoxy coatings including water-soluble epoxy coating and water emulsion coating. Water soluble coatings are often called electrophoresis coatings, namely uniform resin soluble in water to form colloidal solution, if the resin charged ions, under the effect of direct current (dc), the colloid particle electrophoresis available in workpiece surface discharge deposition.

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Diethyl toluene diamine(DETDA)  http://www.yaruichem.com