Preparation method of styrene-acrylate copolymer emulsion used in antirust paint

Abstract

The invention relates to a novel method for preparing a styrene-acrylate copolymer emulsion used in antirust primer paint. The method comprises steps that: (1) phosphate ester functional monomers are subject to a polymerization reaction; two hydroxyl groups of each phosphate ester group are subject to a chelation reaction on the metal surface, such that a dense phosphate ester (salt) protective film is formed on the metal surface, and water molecules and other salt ions are prevented from contacting the metal; the introduced phosphate ester group assists in improving the adhesion of painted coatings on metal surfaces, and in improving the antirust capacity of the painted coatings; (2) diacetone acrylamide (DAAM) and adipic dihydrazide (ADH) form a cross-linking system of the antirust emulsion; hydrazine groups in hydrazino-(NH2-NH2) and ketone groups in the DAAM (C=O) are subject to a dehydration condensation reaction, wherein the ketone groups are copolymerized on the copolymer; through outer cross-linking, a emulsion film with a three-dimensional reticular structure is obtained; (3) an emulsifying system is formed by combining a reactive anion emulsifier and a non-ion emulsifier, such that problems of emulsion deposition and gelling are solved. With the method provided by the invention, an aqueous emulsion with a high solid content is prepared, and water resistance and weathering resistance of the antirust paint is improved.

Description

technical field [0001] The invention belongs to the technical field of polymer material preparation, and in particular provides a method for preparing a styrene-acrylate copolymer emulsion for antirust coatings. Background technique [0002] The annual economic loss caused by metal corrosion in the world is about 700-1 trillion U.S. dollars, which is about 6 times the sum of economic losses caused by natural disasters such as earthquakes, floods, and typhoons, accounting for 2%-4% of the gross national product (GDP) of various countries. %. In order to reduce the loss caused by corrosion, people have taken many measures over the years, but so far, anti-corrosion coatings are still the most effective, economical and widely used. [0003] Acrylate polymer (PA) has a saturated structure in the main chain, so the coating with acrylate copolymer as the film-forming substance has excellent outdoor aging resistance, gloss and color retention, and is the most important film-forming...

AI Technical Summary

Problems solved by technology

This method aims at problems such as flash rust, poor paint film compactness, and poor salt water resistance that occur when water-based styrene-acrylic emulsion is used in antirust coatings. Starting from monomer, emulsifier and molecular design, acrylate monomer, styrene etc. as the main monomer, phosphate ester functional monomer APE-2005 and room temperature cross-linking monomer DAAM are functional monomers. In the presence of reactive emulsifiers, water-based anti-flash rust and excellent dry and wet adhesion can be obtained. Styrene-acrylate copolymer emulsion for rust paint