Preparation method and application of core-shell polyurethane/acrylic acid composite emulsion

Abstract

The invention relates to a preparation method and application of core-shell polyurethane / acrylic acid composite emulsion. The preparation method includes steps of (1), pre-polymerizing hydroxyl acrylate and isocyanate which are equal in equivalent weights for 1-5 hours, adding macromolecular polyhydric alcohol with the equivalent weight equal to that of the hydroxyl acrylate or the isocyanate into the mixture to react for 1-5 hours to obtain prepolymer with double bonds; (2), stirring and mixing the prepolymer synthesized in the step (1) with acrylic acid or methacrylic acid, olefin monomers, hydroxyl acrylate monomers, initiators and chain transfer agents; (3), using co-solvents accounting for 5-20wt% of the total mass of mixed monomers for bottoming, dripping the mixed monomers at the temperature ranging from 80 DEG C to 150 DEG C for 2-5 hours, keeping the temperature unchanged for 4 hours after finishing dripping; (4), reducing the temperature of the mixture to be 90 DEG C, and adding neutralizers for neutralizing the mixture; and (5), reducing the temperature of the mixture to be 60 DEG C, and adding water into the mixture to realize self-emulsification to obtain the core-shell polyurethane / acrylic acid composite emulsion with the solid contents of 42-45wt%. The obtained emulsion is combined with crosslinking components, and is applicable to producing low-VOC (volatile organic compound) water-base coil coatings.

Description

technical field [0001] The invention relates to a preparation method and application of a core-shell type water-based polyurethane / acrylic resin for coil coatings, in particular to a preparation method and application of a water-based core-shell type polyurethane / acrylic resin. Background technique [0002] Coil coating is applied to the surface of steel plate and aluminum by roller coating, and then made into pre-coated coil (color-coated plate). Coil coating was first successfully developed by Hunter Engineering Company in 1937, and it developed rapidly after World War II. Because its process is a high-speed continuous operation, it can reduce costs and pollution for users, and it has beautiful appearance, bright colors, and strength High heat resistance, good melting resistance, convenient processing and molding, etc., the application field is more and more extensive. At present, the importance of coil coatings in industrial coatings is second only to automotive coatings...

AI Technical Summary

Problems solved by technology

[0004] Coatings for pre-coated coils are an important field in the coatings industry. Due to factors such as performance and economy, and the transformation of coating equipment, the production process is still dominated by solvent-based coatings. Currently, only a small amount of them are used in Europe, America and other regions in the world. Water-based coatings, there is no report on production and application in China

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