Water-soluble inorganic zinc-rich paint and preparation method thereof

Abstract

The invention provides a water-soluble inorganic zinc-rich paint and a preparation method thereof. The preparation method comprises the following steps: dropwise adding aluminum-modified silica sol into potassium silicate solution with low modulus, so as to obtain a high-modulus potassium silicate solution as a binder; and adding a catalyst, a siloxane oligomer and a modifier to ensure that the high-modulus potassium silicate solution are uniform in size distribution, and does not have gelatinization reaction for a long time, wherein after the high-modulus potassium silicate solution and a zinc powder mixture are stirred uniformly, the zinc-rich paint has the advantages that reaction rates of all parts of a coating are uniform, and no stress concentration phenomenon exist. Proved by experiments, the zinc-rich paint provided by the invention has no gel after being stored for 90 days at 50 DEG C, the thickness of a film formed once can reach 200 mu m, no cracking or bubbling phenomenon exists, construction can be carried out after the treatment level of the steel surface reaches Sa2, and the salt fog resistance of the coating can reach 10000 hours.

Description

technical field [0001] The invention relates to a zinc-rich paint, in particular to a water-based inorganic zinc-rich paint with modified potassium silicate as a main binder and a preparation method thereof. Background technique [0002] The water-based inorganic zinc-rich coating uses high-modulus silicate as the main binder, and the silicate and zinc powder react and cross-link to form a film under certain conditions. Since the standard potential of zinc is lower than that of steel, when the corrosive medium penetrates, the steel and zinc powder form a primary battery, the zinc powder loses electrons as the negative electrode of the primary battery, and the steel receives electrons as the positive electrode to be protected. In addition, the dissolved zinc ions combine with the anions in the corrosive medium to form basic zinc salts and zinc-iron double salts, which fill the cracks in the coating film to achieve the purpose of isolation and rust prevention. Therefore, wate...

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Problems solved by technology

[0003] However, due to problems such as uneven particle size distribution and poor stability of the high-modulus silicate water-based inorganic zinc-rich coating liquid components during the preparation process, the coating will gel during storage and cannot be applied.

At the same time, the coating is prone to disadvantages such as poor toughness, cracking, chipping, and poor early water resistance after construction and curing. The above coating problems are more likely to occur on the surface of substrates such as steel with low surface treatment

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