Polymeric dispersant for water-based paint and preparation method thereof

Abstract

The invention discloses a polymeric dispersant for water-based paint and a preparation method thereof. The polymeric dispersant is prepared by polymerizing a styrene-maleic anhydride copolymer, ethylene glycol monoethyl ether and polyethylene glycol. The preparation method comprises the following steps: 1, adding the styrene-maleic anhydride copolymer, ethylene glycol monoethyl ether, polyethyleneglycol and a solvent into a reaction kettle, adding an initiator and a neutralizer aqueous solution, and carrying out a constant-temperature reaction at 60-120 DEG C for 2-12 hours. In the invention,the structure of the polymer dispersant contains a plurality of anchoring groups such as benzene rings, hydroxyl and the like; therefore, the water-based pigment dispersing agent can generate a strong adsorption effect with the surface of pigment, has an excellent dispersing effect on inorganic pigment and organic pigment, and can reduce the viscosity of a dispersing system, improve the flowability and fineness of the dispersing system and improve the storage stability of a coating when being used for dispersing the pigment in a water-based system.

Description

technical field [0001] The invention relates to a polymer dispersant for water-based paint and a preparation method thereof, belonging to the technical field of paint additives. Background technique [0002] As a coloring material, pigments are widely used in coatings, printing inks, plastics, rubber, textile printing, wax products, cosmetics and other fields. The vast majority of pigments used in coatings exist in the form of agglomerates and aggregates of primary particles. It is necessary to disperse these pigment particles of different sizes into smaller particles or primary particles, and make them no longer aggregated or aggregated. Stable dispersion system of flocculation, otherwise the coating will have problems such as flocculation, coarsening, precipitation, color drift, floating color, gloss reduction, tinting strength and hiding power, etc., which will affect the performance of the coating. With the improvement of people's requirements for health and environment...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the dispersants for pigments in water-based paints are traditional dispersants, which have a relatively low molecular weight, have a strong affinity for inorganic pigments, and have a good dispersion effect (inorganic pigments are mainly composed of ions, and the surface is acidic, alkaline or amphoteric. Active center, surface polarity, easy to adsorb), but the dispersion effect on organic pigments (such as: carbon black, phthalocyanines, etc.) is poor (organic pigments are usually low polar or non-polar, difficult to adsorb )

In addition, the hydrophilic group of the traditional dispersant is not firmly adsorbed on the surface of the pigment, and it is easy to desorb from the particle surface, resulting in the re-aggregation or precipitation of the dispersed particles, and because the carbon chain length of the lipophilic group is short, it cannot Forming effective steric hindrance, the long-term stability of the system is not good, which will have adverse effects on the appearance, hardness and aging resistance of the coating film