Modified waterborne polyurethane resin, its preparation method and application

Abstract

The invention provides a modified water-based polyurethane resin, its preparation method and application. The resin is prepared by the reaction of an isocyanate-terminated prepolymer and a modified monomer. The preparation method includes the following steps: synthesizing the isocyanate-terminated prepolymer Mix and dissolve the monomer with modification function and the isocyanate-terminated prepolymer, and disperse under high-speed shear after neutralization to obtain a pre-modified emulsion. Add an initiator to the pre-modified emulsion to initiate polymerization The polyurethane resin of the present invention can be used for the preparation process of the modified water-based polyurethane resin prepared by the preparation method provided by the invention in the field of coatings, especially wood varnishes. The preparation process is simple and controllable. application performance requirements.

Description

technical field [0001] The invention belongs to the field of wood lacquer coatings, in particular to a modified waterborne polyurethane resin, its preparation method and application. Background technique [0002] In recent years, under the constraints of increasingly strict environmental protection laws in various countries, the market share of water-based wood coatings has increased year by year. At present, the usage rate of water-based wood coatings in Germany has reached 70%, and that of the United States has reached 80%. The annual output is increasing at a rate of 9%. . However, the application performance of wood lacquer coatings needs to be improved. Compared with solvent-based coatings, its hardness is lower, and its adhesion to primers is poor. The effect of sealing primers alone is poor, the fullness is poor, the early anti-adhesion is poor, and the anti-staining ability Poor etc and overpriced. Therefore, it is necessary to develop a wood paint resin with high ...

AI Technical Summary

Problems solved by technology

[0003] Chinese patent application CN108623751A discloses a preparation method of acrylate-modified water-based polyurethane for water-based wood lacquers. The sulfonate is used as the hydrophilic center. The sulfonate is a strong acid and strong alkali salt with a high degree of ionization. A very small amount can provide strong hydrophilicity, but its characteristic is that it is difficult to prepare small particle size penetrating emulsion. It is difficult for customers who have wet film penetration requirements for wood paint to meet their performance requirements. It has a certain application limitation

[0004] Chinese patent application CN106279620A discloses a modified waterborne polyurethane resin for wood lacquers and its preparation method, which describes a coating film with fast drying speed, glossiness above 90°, high pencil hardness and excellent water resistance However, due to the ethanol-soluble properties of castor oil in the formula system, its chemical resistance and alcohol resistance are poor, which cannot meet the chemical resistance requirements of high-end wood lacquers.

The modified water-based polyurethane and its modified monomer acrylate are widely used in the field of wood coatings due to their performance advantages and price advantages. However, pure acrylic resins have the characteristics of low fullness, poor indentation resistance, and poor film-forming properties. Can not meet the performance requirements of wood coatings

However, the traditional water-based polyurethane resin cannot meet the performance requirements of wood lacquers due to its low hardness, slow drying speed and poor resistance.

Images