A dispersant for paper coating is an essential chemical in the paper industry, primarily functioning to maintain uniform and stable suspension of coating pigments (such as kaolin and calcium carbonate) in aqueous systems. During coating color preparation, fine pigment particles tend to flocculate due to their large specific surface area and high surface energy, leading to increased viscosity and poor flowability. The dispersant adsorbs onto pigment surfaces through its active components, generating powerful electrostatic repulsion or steric hindrance that effectively prevents particle aggregation and sedimentation. This mechanism enables the coating color to maintain ideal rheological properties, ensuring the formation of uniform and smooth coating layers on paper surfaces. Consequently, it significantly enhances the finished paper's gloss, whiteness, smoothness, and printability, while improving production efficiency and reducing energy consumption, making it an indispensable additive in modern high-quality paper manufacturing.