Waterborne two-component varnish and preparation method thereof

Abstract

The invention discloses waterborne two-component varnish and a preparation method thereof. The waterborne two-component varnish is formed by mixing a component A and a component B in the mass ratio of(2.5-3.5):1, wherein the component A comprises, by weight, 25-40 parts of waterborne acrylic resin, 25-40 parts of waterborne polyester resin, 0.1-1 part of base material wetting agent, 0.1-1 part offlatting agent, 0.1-1 part of defoaming agent, 0.1-1 part of ultraviolet absorbent, 0.1-1 part of bactericide, 5-10 parts of cosolvent, 0.1-1 part of thickening agent and 2-5 parts of carboxymethyl chitosan; the component B comprises, by weight, 40-60 parts of isocyanate curing agent, 0.1-1 part of adhesion promoter and 40-60 parts of cosolvent. The fullness, glossiness, flatting property, construction performance and mechanical properties of the varnish can reach the standards of high-performance oily varnish and are higher than those of existing waterborne varnish, and the varnish has the advantage of being low in content of VOCs.

Description

technical field [0001] The invention belongs to the field of paint preparation, in particular to a water-based two-component varnish for vehicles. Background technique [0002] Coating refers to a substance that can be applied to the surface of an object, firmly bonded to the surface, and forms a solid film with a certain strength. [0003] Varnish, also known as varnish, is a coating composed of resin as the main film-forming substance plus a solvent. Since the coating and the coating film are transparent, it is also called transparent coating. Must have several functions: 1. Good appearance: including high fullness, high gloss, good leveling, no shrinkage cavity, no prickly heat, etc.; 2. Excellent protection performance: including good hardness, good flexibility, weather resistance Good, good water resistance, good salt spray resistance, etc.; 3. Excellent construction: including good wettability, not easy to sag; 4. Wide construction window: including good adaptability ...

AI Technical Summary

Problems solved by technology

[0005] Because topcoat and varnish are roughly the same in terms of composition and function, the biggest difference is that the topcoat contains color paste, so the problems of varnish can be obtained by analyzing the defects of existing topcoat, such as patent CN105482588A "An Environmentally Friendly Nano-Metal Auto Finish" discloses an automotive finish. This patent combines the treated nano-metal powder with other substances to finally obtain a top coat with excellent performance. It is based on conventional resin components. Adding metal powder in the process increases the steps, increases the cost, and has certain requirements for the metal powder; the patent CN106800874A "A water-based two-component polyurethane topcoat and its preparation method" discloses that it is mainly composed of hydroxyacrylate and isocyanate curing agent As the main component, but the curing agent contains both hydrophilic and hydrophobic polyisocyanate curing agents, and the content of water-based hydroxyl acrylic dispersion in component A is high, and the acid and alkali resistance of the product is unbalanced

[0006] As a two-component acrylic varnish, traditional water-based acrylic resin coatings have defects such as easy water loss, high light absorption, hot stickiness, cold brittleness, and environmental sensitivity. As far as varnishes are concerned, there are still gaps in the fullness, gloss, leveling, and workability of the paint film.

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