The invention belongs to the technical field of wood composite materials, and particularly relates to a
polyurea color-changing agent microcapsule and a preparation method thereof, a
formaldehyde-free compound
adhesive, a reversible thermochromic
formaldehyde-free recombined decorative
veneer and a preparation method thereof. The preparation method comprises the following steps: mixing a water-soluble emulsifier with water to obtain a water phase; a compound color changing agent and a diisocyanate compound are mixed, an
oil phase is obtained, and the compound color changing agent comprises thermosensitive fluorane dye, a color developing agent and an
organic solvent; emulsifying the water phase and the
oil phase to obtain an
emulsion; and carrying out
polymerization reaction on the low-activity
polyamine compound and the high-activity
polyamine compound and the
emulsion to obtain the
polyurea color-changing agent microcapsule. According to the color-changing agent, the microcapsules and the
polymer are cross-linked, so that the
interface bonding force and the
dispersion stability are improved, the stability and the
weather resistance of the color-changing agent are remarkably improved, and meanwhile, the damage to the microcapsules during high-pressure gluing of the recombined decorative material is reduced. According to the recombined decorative
veneer, the thermochromic function is achieved, the decoration performance of the recombined decorative
veneer is improved, intelligence and interactivity are improved, and zero addition of
formaldehyde is achieved.