Method for preparing acrylate copolymer emulsion for aqueous metal protective paint

Abstract

The invention relates to a method for preparing an acrylate copolymer emulsion for an aqueous metal protective paint, which comprises the following steps: step 1, providing raw materials comprising methyl methacrylate as a main monomer, butyl acrylate as the main monomer, a functional monomer, an anion type emulsifying agent, a non-ion type emulsifying agent and an initiating agent; step 2, mixing all the monomers in the raw materials and 45 to 55 percent of the emulsifying agent in amount of calculation with water, and stirring the mixture at a high speed for pre-emulsification so as to prepare pre-emulsification monomers; step 3, adding the residual emulsifying agent in the step 2 into a vessel, raising the temperature to between 48 and 52 DEG C, beginning to add 35 to 35 percent of thetotal amount of the initiating agent, and adding 8 to 12 percent of the pre-emulsification monomers at a temperature of between 58 and 62 DEG C; step 4, beginning to preserve heat at the time of heating up to a temperature of between 78 and 82 DEG C until blue light occurs, reacting for a period of time, beginning to adding the pre-emulsification mixed monomers dropwise when the system has no back flow, controlling the temperature between 85 and 89 DEG C, finishing dropping within 3 to 4 hours, and at the same time, and dropwise adding the residual initiating agent aqueous solution in the step 3 for 3.5 to 4.5 hours; and step 5, heating up the system up to higher than 88 to 92 DEG C, reacting by preserving the heat for 0.5 to 1 hour, cooling the system below a temperature of between 38 and 42 DEG C, and adjusting a pH value to between 8.5 and 9 by organic amine.

Description

technical field [0001] The invention relates to a method for preparing an acrylic polymer, in particular to a method for preparing an acrylic polymer emulsion for a water-based metal protective paint. Background technique [0002] At present, the metal protective coatings widely used at home and abroad mainly use solvent-based resins as base materials, which contain a large amount of organic solvents, such as: benzene, xylene, vinyl acetate, etc., and these volatile organic compounds volatilize to The environment not only endangers the construction personnel, but also volatilizes into the atmosphere, causing environmental pollution and waste of resources. With the enhancement of human's awareness of environmental protection, countries around the world have issued corresponding environmental protection regulations to limit the emission of volatile organic compounds in coatings. It is imminent to develop environmentally friendly green metal protective coatings. Due to environ...

AI Technical Summary

Problems solved by technology

Among water-based paints, wall paints are at the forefront with their own water-based and low volatile organic compounds (VOC: volatile organic compounds). However, special paints for metal protection are relatively lagging behind because they involve many factors. There is therefore a need to strengthen this area

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