Preparation method of hydroxy-polyacrylate aqueous dispersion and waterborne paint containing hydroxy-polyacrylate aqueous dispersion

Abstract

The invention relates to a preparation method of hydroxy-polyacrylate aqueous dispersion, belonging to the field of the organic polymer compound. The method comprises the following steps: (1) mixing hydroxy-polyacrylate with carboxylate and hydroxy-polyacrylate without carboxylate in a weight ratio of 1:0.1-3, adding deionized water which is 1-10 times of hydroxy-polyacrylate with carboxylate by weight to emulsify; and (2) distilling to removing solvent and ensure that the solid content is 40-70%, and adjusting the pH value to 6-8 to obtain the hydroxy-polyacrylate aqueous dispersion. The aqueous dispersion prepared by the method has high solid content and a core-shell structure; the film-forming property of the two-component waterborne acrylate paint can be increased, the fullness of the film can be improved; and the aqueous dispersion has excellent dispersibility to isocyanate curing agent and good compatibility with the curing agent and the luster and decoration performance of the film can be increased. The hydroxy-polyacrylate aqueous dispersion prepared by the method of the invention can be used to prepare the two-component waterborne acrylic paint.

Description

technical field [0001] The invention belongs to the field of organic polymer compounds, and relates to a polymer compound obtained by reacting only carbon-carbon unsaturated bonds, in particular to polyacrylate. Background technique [0002] With the enhancement of environmental awareness and the improvement of environmental regulations, the use of volatile organic compounds (VOC) and harmful air pollutants (HAP) in traditional solvent-based coatings has become more and more restricted, so water-based coatings are increasingly being used by people. focus on. One-component waterborne polyurethane coatings cannot compete with solvent-based coatings, while two-component waterborne polyurethane coatings have high performance and multiple functions, which can meet the needs of high-end coatings. Therefore, two-component waterborne polyurethane coatings are the development direction and research hotspot of waterborne coatings. The two-component water-based polyurethane coating is...

AI Technical Summary

Problems solved by technology

U.S. Patents USP425150 (2003.04.29) and USP246929 (2005.10.07) reported the introduction of ketone-containing carbonyl-containing cross-linking monomers to polymer chain segments as active sites, and cross-linking occurred after the pH value of the system changed during the film-forming stage. The reaction forms a cross-linked polymer network, which eliminates the influence of the remaining hydrophilic groups in the coating film, but there are high cross-linking monomer content (up to 25% of the total monomer amount), high cost, and poor emulsion polymerization stability. The storage period of the polymer emulsion is short and other shortcomings; U.S. Patent USP887626 (2004.07.09) reported the use of two-component blending with different reactivity, and introduced a third component to control the reaction process between the two components, synthesized A self-crosslinking water-based coating

Because the system contains more than two components, the construction cost is high and other defects

At present, the following problems generally exist in the aqueous dispersion of hydroxyl polyacrylate: (1) the solid content of the dispersion is low, generally 20-40%; (2) the content of hydrophilic groups in the dispersion is relatively high, and the remaining The hydrophilic carboxylate in the film will reduce the performance of the coating film; (3) the compatibility between the aqueous dispersion of hydroxyl polyacrylate and isocyanate is poor, and the two-component coating film prepared with it has poor appearance and low gloss, which is difficult to meet Application requirements of automotive coatings

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