Moisturecured one-component polyurethane paint and preparation method thereof

Abstract

The invention relates to moisturecured one-component polyurethane paint and a preparation method thereof. The polyurethane paint comprises the following raw materials in percentage by weight: 10%-20% of polyisocyanate monomer, 20%-40% of polyether polylol, 5%-15% of plasticizer, 30%-50% of modified mineral powder, 1%-5% of latent curing agent, 0.1%-2% of environment-friendly catalyst covered with cyclodextrin, 0.1%-1% of defoamer and 0.1%-1% of mono-isocyanate compound, wherein the modified mineral powder is mineral powder of which the surface is covered with a covered agent by a chemical covering method; and the environment-friendly catalyst covered with the cyclodextrin is in a nanometer cavity of the cyclodextrin, and the cyclodextrin is unmodified cyclodextrin or modified cyclodextrin or the composition of the unmodified cyclodextrin and the modified cyclodextrin. The moisturecured polyurethane paint disclosed by the invention solves the problem in storage stability of a one-component polyurethane product, and the storage life of the moisturecured polyurethane paint can exceed one year.

Description

technical field [0001] The invention relates to a protective coating, in particular to a protective coating used in the construction field and a preparation method thereof. Specifically, the invention relates to a moisture-curing one-component polyurethane coating and a preparation method thereof. Background technique [0002] Moisture-curing one-component polyurethane coatings are prepolymers containing isocyanate (-NCO) end groups, suitable for construction in humid environments, can react with moisture, and further cross-link and cure to form highly elastic, durable non-joint Seam waterproof coating. The coating film contains a large number of urea bonds and urethane bonds. Due to the effect of hydrogen bonds, the coating film has excellent adhesion, wear resistance, oil resistance, acid and alkali resistance, impact resistance, and good electrical insulation. The film-forming substances of such coatings are mostly prepared by the addition reaction of macromolecular pol...

AI Technical Summary

Problems solved by technology

[0003] However, moisture-curing one-component polyurethane coatings also have some shortcomings: ①The coating is cured by slow reaction by absorbing moisture, so it is greatly affected by air humidity and the curing time is longer. Adding a drier can improve the coating The drying speed of the film, but it will reduce the storage stability; ②Due to the carbon dioxide generated by moisture curing, it cannot be thickly coated, and multiple layers of coating and scraping are required during construction. The procedure is cumbersome, which may affect the construction period; ③The addition of powder can reduce costs, but It will increase the viscosity of the system, and it is necessary to add a diluent solvent, making the product not environmentally friendly

However, in order to ensure the stability of the mechanical properties of the coating film after curing, the amount of water added must be strictly controlled. If the moisture content is too low, the curing of the coating film will be slow. As the water content increases, the mechanical properties increase accordingly. When the water content is in a certain range, the tensile strength is the highest; when the water content is too much, the mechanical properties decrease.

These have caused many difficulties to the application of water-curable polyurethane waterproof coatings, which are also the shortcomings of water-curable polyurethane waterproof coatings.

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