Preparation method of fluorine/silicone co-modified waterborne polyurethane

Abstract

A preparation method of the fluorine / silicone co-modified waterborne polyurethane comprises the following steps: (1) adding diisocyanate, polymer dihydric alcohol, dihydroxy silicone oil, a hydrophilic chain extender and a catalyst dibutyltin dilaurate into a reaction kettle, and stirring all the components at 50-70 DEG C for 90-120 minutes to obtain a prepolymer; (2) adding acetone into the obtained prepolymer to dilute the prepolymer, then adding micromolecular fluorine substituted alcohol, micromolecular dihydric alcohol and a cross-linking agent, and continuously performing the reaction at50-70 DEG C for 90-120 minutes; (3) reducing the temperature of the reactant to 30-40 DEG C, adding a neutralizer triethylamine, and uniformly stirring the reactant; and (4) adding a diamine chain extender and water, carrying out high-speed emulsification, and finally carrying out reduced pressure suction filtration to remove acetone so as to obtain the product. Due to the adoption of a fluorine / silicone co-modification process, the waterproof and antifouling properties of the obtained waterborne polyurethane can be improved by more than 30%, and the waterborne polyurethane has good stabilityand lower production cost.

Description

technical field [0001] The invention relates to the field of polyurethane synthesis, and relates to a preparation method of fluorosilicon co-modified waterborne polyurethane. Background technique [0002] Water-based polyurethane uses water as a solvent, which is non-toxic, environmentally friendly, and has the advantages of convenient processing and use. Therefore, it has a wide range of uses in fabric coating and leather top coating. However, due to the addition of hydrophilic monomers, ordinary water-based polyurethane has poor waterproof and anti-fouling capabilities. Modification with pure silicone can improve the hydrophobicity of polyurethane to a certain extent and reduce the surface energy of polyurethane, but its antifouling and waterproof ability can only be improved to a limited extent. Simple organic fluorine modification can also reduce the surface energy of polyurethane to a large extent, but to achieve higher waterproof and antifouling ability, more organic ...

AI Technical Summary

Problems solved by technology

However, due to the addition of hydrophilic monomers, ordinary water-based polyurethane has poor waterproof and anti-fouling ability.

Modification with pure silicone can improve the hydrophobicity of polyurethane to a certain extent and reduce the surface energy of polyurethane, but its antifouling and waterproof ability can only be improved to a limited extent.

Simple organic fluorine modification can also reduce the surface energy of polyurethane to a large extent, but to achieve higher waterproof and antifouling ability, more organic fluorine needs to be added, and adding too much will affect the water solubility and long-term storage of waterborne polyurethane Stability, and the production cost is also greatly increased

Chinese patent application 201010115181.4 introduces a single-component silicon / fluorine modified water-based polyurethane resin and its preparation method, and Chinese patent application 201310368406.0 introduces a silicon-fluorine double-modified water-based polyurethane emulsion and its preparation method. The above two documents introduce Most of them are silicon-fluorine-modified water-based polyurethanes used in architectural emulsions and coatings, and silicon-fluorine-modified water-based polyurethanes used in textile fabrics have not been reported yet.

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