This invention relates to the field of organic
pigment technology, specifically to a green organic
pigment and its preparation method. This invention overcomes the problems of poor dispersibility and weak tinting strength in green organic pigments. After pre-oxidizing
phthalocyanine green
pigment, it is placed in a high-
pressure reactor along with an intercalating agent. The extremely strong permeability of
supercritical carbon dioxide fluid is utilized for pressure-maintained
permeation, followed by instantaneous
pressure release to generate a micro-explosion effect, which non-destructively exfoliates the pigment aggregates into primary nanoparticles. Subsequently, under the
coupling of a co-
solvent and ultrasonic / high
shear force field, terminal amino-terminated hyperbranched
polyamide ester is used for covalent
grafting. A double-layer protective film constructed from modified
rosin and a
silane coupling agent is then introduced. Finally, the finished product is obtained through in-situ
silica coating and surfactant-assisted vacuum freeze-
drying. The obtained pigment
powder exhibits a loose, porous structure, without hard agglomerates, and possesses excellent
dispersion stability and high tinting strength in organic systems.