High-solid surface-tolerant epoxy zinc-rich primer and preparation method and application thereof

Abstract

The invention relates to a high-solid surface-tolerant epoxy zinc-rich primer. The primer is prepared from a component A and a component B according to a weight ratio of (16-20):1; the component A comprises the following components in parts by weight: 5-9 parts of liquid phenolic epoxy resin, 6-15 parts of E20 solid epoxy resin, 0.5-1.5 parts of an active diluent, 0.1-0.3 part of a dispersing agent, 70-80 parts of main rust-proof pigment, 2-6 parts of chemical anti-rust pigment, 1.5-2.5 parts of an anti-settling agent and 3-4 parts of an organic mixed solvent; and the component B comprises thefollowing components in parts by weight: 1.5-2.5 parts of a polyamide curing agent, 2-3 parts of a Mannich base curing agent, 0.3-0.6 part of a silane coupling agent and 0.2-0.6 part of an organic mixed solvent. The invention also relates to a preparation method of the primer and a coating film. The primer is high in solid content and low in VOC content, is resistant to corrosion, has a long effect, has good adhesive force and salt fog resistance, and is particularly suitable for repairing and maintaining equipment in industries such as chemical industry, thermoelectricity, machinery and thelike.

Description

technical field [0001] The invention belongs to the technical field of coatings, and in particular relates to a high-solid low-surface treatment epoxy zinc-rich primer and a preparation method and application thereof. Background technique [0002] Epoxy zinc-rich primer is a kind of epoxy resin as film-forming substance and amine or modified amine adduct as curing agent, adding ultra-fine zinc powder, as well as additives and solvents, coated on the surface of steel substrates , which acts as a sacrificial anode to protect the steel base material of the cathode from being corroded, because zinc is more active than iron, and when the electrochemical reduction oxidation reaction occurs, Zn loses electrons in the anode region and becomes Zn 2+ ions, zinc powder is consumed and corroded, divalent Fe in the cathode area 2+ The gained electrons are reduced to Fe, thus the cathode is protected against corrosion. It is widely used in heavy anti-corrosion protection in the fields o...

AI Technical Summary

Problems solved by technology

[0003] Since the zinc-rich paint contains a large amount of zinc powder, after the paint is formed into a film, there are many pores. When the film thickness of one-time coating is too large, it is easy to crack; Consumption, produced a large amount of water-soluble Zn 2+ , will lead to an increase in osmotic pressure, which is extremely easy to cause rust and blistering of the substrate, so its long-term anti-corrosion protection is limited

In addition, in the process of welding and cutting, a large amount of zinc vapor will be generated, which will cause the "zinc fever" of the staff

[0004] Epoxy zinc-rich coatings mainly include traditional epoxy zinc-rich primers, high-solid epoxy zinc-rich, solvent-free epoxy zinc-rich, and water-based epoxy zinc-rich. There are also many reports in domestic literature and patent reports. For example, the invention patent with the publication number CN102533052B discloses a solvent-free epoxy zinc-rich primer and its preparation method. It has no solvent volatilization, is economical and environmentally friendly, and has excellent salt spray resistance. However, the viscosity of the solvent-free epoxy zinc-rich primer is Large, inconvenient construction, when using roller coating construction, the construction efficiency is low, and when using double-tube feed airless spraying, because of the short mixing period, it is easy to block the gun; the invention patent of publication No. CN103483983B is an epoxy rich Zinc primer and preparation method thereof discloses a solvent-based epoxy zinc-rich primer, which has low solid content and high VOC content, and needs to be sprayed 2-3 times to reach the specified film thickness of the salt spray test sample; the publication number is CN100451079C Invention patent two-component epoxy zinc-rich primer and its manufacturing method, an epoxy zinc-rich primer with a zinc content of more than 80% is announced, which has excellent anti-corrosion performance and convenient construction, but the thickness of its primary coating film is limited. High requirements for surface treatment, inconvenient for maintenance and use

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