Solvent-resistant dilution type polyurethane ink binder and preparation method and application thereof

The invention belongs to the technical field of intaglio ink printing, particularly relates to a solvent-resistant dilution type polyurethane ink binder, particularly relates to a polyurethane binderfor flexible package intaglio printing composite ink with excellent solvent dilution resistance, boiling resistance and anti-blocking performance, and further discloses a preparation method of the polyurethane binder for flexible package intaglio printing composite ink. According to the polyurethane binder for flexible package intaglio printing composite ink, reaction is performed on cross-linkedpolyol and isocyanate, then the polyurethane resin is subjected to cross-linking reaction again by using a cross-linking agent, and a double-cross-linked network-shaped three-dimensional structure isintroduced into polyurethane synthesis. According to the invention, the movement of molecular chains is limited, the solvent molecules are difficult to permeate, the solvent dilution resistance of thepolyurethane resin is enhan