Study On Preparation And Application Of Acrylic Latex For High-gloss Metallic Coating

With the promotion and popularization of water-based coatings,in areas where anti-corrosion requirements are not high,the comprehensive performance of single-component water-based coatings has been comparable to similar solvent-based coatings.Among them,water-based alkyd resins occupy the main market in the field of light corrosion due to their low molecular weight and high film-forming gloss.However,they also have disadvantages such as slow drying rate,poor weather and early water resistance.The water-based acrylic resin exhibits excellent weather resistance,and gloss and color retention in applications,and the synthetic modification technology is mature.Therefore,the structure of the water-based acrylic resin can be modified and designed to improve its gloss and early water resistance.The purpose of this paper is to introduce a double self-crosslinking system containing organosiloxane and ketone hydrazine by emulsion polymerization,develop a high gloss acrylic latex for metallic paint,and explore its application properties.In this paper,using styrnen(St)as the hard monomer,butyl acrylate as the soft monomer,diacetone acrylamide(DAAM)/ adipic acid dihydrazide(ADH)and silane ethenyltrimethoxy(A-171)as the functional monomer.The acrylic latex is synthesized by semi-continuous seeded emulsion polymerization.The studies have shown that the solid content of acrylic latex is 48 %,when the amount of seed emulsion is 5 %,the amount of SDS accounts for 2.5 % of the total monomer,the ratio of St and BA is 2:1,the amount of DAAM accounts for 1 % of the total monomer,the amount of A-171 accounts for 0.5 % of the total monomer,the amount of APS accounts for 0.4 % of the total monomer,the amount of NDM accounts for0.5 % of the total monomer,the amount of AA accounts for 2 % of the total monomer,the synthesized acrylic latex has a high monomer conversion rate and a narrow particle size distribution range.The paint film has excellent adhesion to the metal substrate,high gloss and excellent early water resistance.The self-made acrylic latex was used as the base material to prepare the metallic paint,and the influence of various factors on the application performance of the metallic paint was systematically investigated.The experimental results show that the amount of film-forming aid DPn B accounts for 5 % of the amount of acrylic latex,the ratio of pigment to base is 0.8,the amount of dispersant BYK-190 accounts for9 % of the amount of pigment,the neutralizer is DMEA,and the prepared metallic paint is stable in heat storage good performance,excellent adhesion to a variety of metal substrates,high coating gloss,excellent early water resistance and salt spray resistance.Meanwhile,the self-made acrylic latex and water-based alkyd resin are cold blended,and the resulting coating can not only improve the slow drying and poor water resistance of the coating when the alkyd resin is used alone,but also can significantly improve the gloss of the acrylic resin coating.