High-performance water-based two-component finish paint composition as well as preparation method and use thereof

Abstract

The invention discloses a high-performance water-based two-component finish paint composition, which is prepared finish paint and a curing agent, wherein the finish paint is prepared from the following components in parts by weight: 60-75 parts of water-based hydroxyl acrylic resin, 0.3-1.1 parts of a flatting agent, 0.3-1 part of an antifoaming agent, 1-4 parts of a dispersing agent, 2-30 parts of pigment, 5-15 parts of deionized water, 0-0.5 part of a pH regulating aid and 0-11.6 parts of other additives; the curing agent is prepared from the following components in parts by weight: 55-75 parts of isocyanate, 25-45 parts of a solvent and 0-1 part of a water removal agent. The finish paint composition provided by the invention has good construction performance and paint film property, andis lower in content of volatile organic compounds (VOCs), thus being used for finish paint for buses.

Description

technical field [0001] The invention relates to the technical field of coatings, in particular to a high-performance water-based two-component topcoat composition, a preparation method and an application. Background technique [0002] With the rapid development of China's economy, environmental problems have become increasingly prominent, and people's calls for environmental protection are also increasing. To this end, in recent years, local governments have successively issued environmental protection regulations to regulate VOC emissions in the coating and painting process. For the painting of vehicles such as buses and large-scale equipment, the 2K topcoats currently used are mainly solvent-based coatings. The current GB24409 standard for this type of product is VOC≤630g / L, which is ≤150g / L compared to water-based 2K topcoats. Even VOC levels ≤100g / L are too high. Therefore, in terms of reducing VOC emissions, the water-based 2K topcoat is a very good choice. [0003] ...

AI Technical Summary

Problems solved by technology

[0004] First, the latent heat of water volatilization in water-based coatings is large, which is greatly affected by air humidity, and is prone to pinholes and sags;

[0005] Second, the surface tension of water in water-based coatings is high, which has high requirements on the construction process and substrate, and shrinkage cavities are more likely to appear;

[0006] Third, for systems with high performance requirements, water-insoluble resins are generally used, resulting in the final film-forming material being heterogeneous film-forming, and the fullness and gloss are often difficult to meet high requirements

[0015] Ordinary isocyanate curing agent, because it is relatively hydrophobic, cannot be well dispersed in the water phase when it is mixed with the main paint, which will cause poor luster and plumpness of the paint film, and prone to shrinkage; The isocyanate modified by acid salt will increase the hydrophilicity, improve the reflection state of the isocyanate and the main paint in water after mixing, and it is easy to achieve a better paint film appearance. Due to the introduction of the hydrophilic structure of the curing agent, it is easy to cause paint film The water resistance and chemical resistance are reduced, and when the coating film is thicker, it is prone to pinholes

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