A kind of hydroxyl polyacrylate emulsion and its preparation method and application

Abstract

The invention discloses a hydroxyl polyacrylate emulsion and its preparation method and application. The preparation method comprises weighing acrylate monomers and / or methacrylate monomers, hydroxyl acrylate monomers, acrylic acid monomers, Functional monomers, hydroxyl oligomers, mix well to prepare a monomer mixture, take 10-15% of the monomer mixture and emulsify it with an emulsifier to prepare a seed pre-emulsion for later use; add the emulsifier, sodium bicarbonate and deionized water to the reactor During the process, stir and increase the temperature of the reaction system, add the initiator, stabilize, drop the seed pre-emulsion, stabilize, drop the remaining monomer mixture and the remaining initiator, heat up, mature, cool down, and neutralize , after heat preservation, the temperature is lowered and the material is discharged to obtain a hydroxyl polyacrylate emulsion; the coating film of the water-based two-component polyurethane coating prepared by the hydroxyl polyacrylate emulsion and a water-based polyisocyanate curing agent has high hardness, high gloss and excellent chemical resistance.

Description

technical field [0001] The invention relates to a water-based two-component polyurethane coating, in particular to a hydroxyl polyacrylate emulsion and its preparation method and application. Background technique [0002] Most of the existing wood coatings are solvent-based coatings, which contain more than 50% of organic solvents. These solvents will volatilize into the atmosphere during the construction process to pollute the environment and damage human health, and the organic solvents themselves will cause combustion, explosion, etc. Security risks. Therefore, water-based wood coatings are the development trend of international coatings. Waterborne wood coatings include one-component and two-component water-based wood coatings. Among them, the paint film properties of one-component water-based wood coatings include poor water resistance, chemical resistance and hardness, which are far behind oil-based coatings, which seriously limits the popularization and application ...

AI Technical Summary

Problems solved by technology

However, the polymerization stability of conventional polyacrylate emulsions with high hydroxyl content is poor, and industrial production is unstable.

In addition, excessive use of emulsifiers or improper combination of emulsifiers in emulsion polymerization will reduce the gloss and chemical resistance of the paint film

At present, the hardness and chemical resistance of waterborne two-component polyurethane paint films are improved by increasing the glass transition temperature and hydroxyl content of hydroxyl polyacrylate emulsions, which will also lead to the need for more organic small molecule film-forming aids in the process of paint formulation. agent and curing agent (the curing agent often contains a certain amount of co-solvent), increasing the content of volatile organic compounds (VOC) in the coating will also lead to an increase in the cost of the coating

Therefore, conventional methods are difficult to improve the poor appearance, poor chemical resistance, and low hardness of hydroxyl polyacrylate emulsion two-component paint films.

[0005] Chinese invention patent application CN103059210 modifies the hydroxyl polyacrylate emulsion by adding 2%-5% fluorine-containing acrylic acid monomer, although the water resistance and chemical resistance of the two-component paint film will be slightly improved, due to the fluorine-containing acrylic acid The hydrophobic and oleophobic properties of the ester monomer make the conversion rate of the polymerization reaction not high, which easily causes a large amount of fluorine-containing monomers to remain, and also causes problems such as poor interlayer adhesion of the paint film, and the fluorine-containing acrylate monomer The high price has caused the cost of polymer emulsion to rise sharply, etc.

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