Water-based modified two-component PU finishing coat and preparation method thereof

Abstract

The invention discloses water-based modified two-component PU finish coat and a preparation method thereof, which relate to the technical field of water-based paint, the water-based coat comprises a component A and a component B, the component A and the component B are independently stored and mixed according to the weight part ratio of (5-7): 1 in use, and the component A is prepared from the following raw materials by weight: 45-48 parts of water-based acrylic resin; 0.15 to 0.25 part of a defoaming agent; 0.5 to 0.7 part of a water-based dispersing agent; 0.5 to 0.7 part of fumed silica; 4-6 parts of water-based zinc phosphate; 6-8 parts of talcum powder; 0.3 to 0.5 part of a thickening agent; 3 to 4 parts of dipropylene glycol butyl ether; 7-8 parts of water-based carbon black color paste; 0.2 to 0.3 part of a water-based wetting agent; 0.1 to 0.2 part of water-based wax slurry; 28 to 32 parts of deionized water; and the component B comprises the following raw materials in parts byweight: 35-45 parts of a waterborne polyurethane curing agent; 35-40 parts of a water-based isocyanate curing agent; and 20 to 25 parts of propylene glycol methyl ether acetate. When the water-basedmodified two-component PU finish coat is sprayed on galvanized materials such as cold galvanizing and hot galvanizing, the water-based modified two-component PU finish coat has excellent adhesive force and good overall application effect.

Description

technical field [0001] The invention relates to the technical field of water-based coatings, more specifically, it relates to a water-based modified two-component PU topcoat and a preparation method thereof. Background technique [0002] Water-based coatings are based on a variety of polymer resins and water is the dispersion medium. Compared with traditional solvent-based coatings, they have lower volatile organic compound (VOC) emissions and are green, safe and environmentally friendly coatings. [0003] A Chinese invention patent application document with the publication number CN106800874A discloses a water-based two-component polyurethane topcoat and a preparation method thereof. The water-based two-component polyurethane topcoat is composed of A component and B component, and the A The components are composed of the following components by weight percentage: deionized water 10-15%, wetting and dispersing agent 0.5-1.2%, defoamer 0.1-0.5%, pigment 12-25%, water-based hy...

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Problems solved by technology

[0004] In the above application documents, hydrophilic polyisocyanate and hydrophobic low-viscosity asymmetric isocyanate trimer are blended in a certain proportion to form a curing agent with low viscosity and no additional co-solvent is required. reaction, low VOC content, high cross-linking density of the paint film, and good chemical resistance, but with the development of society, some steel materials need to be galvanized to increase the anti-corrosion and anti-rust effect, and cold-dip galvanized, hot-dip galvanized There are also more and more applications of electro-galvanized sheets, and the above-mentioned water-based polyurethane topcoats have the disadvantages of poor adhesion and multiple spraying on galvanized sheets. Therefore, a new solution needs to be proposed to solve the above problems

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