High-viscosity double-component polyurethane coating and preparation method thereof

Abstract

The invention discloses a high-viscosity double-component polyurethane coating. Firstly, a castor oil crosslinking prepolymer is adopted, wherein a multifunctional group structure of castor oil can endow a polymer with certain crosslinking, accordingly, the crosslinking degree of the polymer is improved, the interaction force of molecular chains is increased, movement of the molecular chains is blocked, water molecules cannot easily enter the molecular chains to swell the polymer, and the water absorption of the coating is reduced; meanwhile, the castor oil is triglycerin of fatty acid, nonpolar fatty acid chains of medium-long chains in molecules of the castor oil enable the coating to have excellent hydrophobicity, and the water absorption is further reduced; besides, ester in the castor oil has higher cohesive energy and can improve the tensile strength of the coating; ethyl cellulose has better heat resistance and thermoplasticity and has good compatibility with polyurethane, and the comprehensive performance of the prepolymer can be improved; the polyurethane prepolymer and polysilsesquioxane are subjected to blending modification.

Description

technical field [0001] The invention relates to a coating, in particular to a high-viscosity two-component polyurethane coating and a preparation method thereof. Background technique [0002] Water-based polyurethane emulsion has the advantages of adjustable hardness, excellent adhesion and flexibility, and is widely used in the fields of coatings, adhesives and inks. At present, the relatively mature anionic water-based polyurethane is synthesized mainly through the synthesis of polyurethane molecular chains. The hydrophilic group is introduced into the segment and internally emulsified. After film formation, it has certain hygroscopicity, and the mechanical properties, water resistance and solvent resistance of film formation are poor. Usually, cross-linking modification and compound modification can be used to improve the water resistance and mechanical properties of the film; [0003] In order to improve the mechanical properties, water resistance and other properties o...

AI Technical Summary

Problems solved by technology

[0002] Water-based polyurethane emulsion has the advantages of adjustable hardness, excellent adhesion and flexibility, and is widely used in the fields of coatings, adhesives and inks. At present, the relatively mature anionic water-based polyurethane is synthesized mainly through the synthesis of polyurethane molecular chains. The hydrophilic group is introduced into the segment to emulsify internally, and the film has a certain degree of hygroscopicity, and the mechanical properties, water resistance and solvent resistance of the film are poor.