Preface:

     In high-end industrial coating systems, the control of Floating&Floating is not simply a matter of aesthetic appeal, but a complex issue related to coating functionality, production stability, and economy. Compared to traditional solutions, there are systematic differences in the mechanism of action, performance, and applicable boundaries of flocculent hyperdispersants based on block polymerization technology. This article analyzes the principle of float color, the advantages and disadvantages of solutions, and the results of application experiments.

1. The first manifestation of industrial coatings

     High end industrial paints, especially automotive repair paints, high-end mechanical equipment coatings, and 3C electronic product coatings, have a coating appearance that is the first reflection of product quality, while floating color and discoloration are common and difficult problems.

     Floating color is essentially caused by the Bernhard vortex flow generated by different pigment particles during the drying process of the paint film, and the particles undergo vertical separation due to differences in particle size, density, and surface energy: pigments with higher density and larger particle size sink (such as titanium dioxide and calcium carbonate), while pigments with lower density and smaller particle size float up (such as carbon black and phthalocyanine blue).

The ideal dispersion state of pigments is uniform between them (to avoid floating and blooming), generally established under the following conditions:

●  Selection of formula materials

Surface energy matching: After surface treatment, the wettability and affinity of different pigments with the resin system tend to be consistent.

Co stabilizing dispersant: using block copolymer dispersant (such as Tech-6320), while providing strong steric hindrance or electrostatic repulsion to multiple pigments to prevent selective flocculation.

Three dimensional network: Adding anti floating color additives or rheological additives to form a three-dimensional network structure in the wet film, limiting the migration of pigment particles but affecting leveling.

●  Process tolerance

Narrow particle size distribution: Each pigment is ground to a similar fineness (usually 5-20 μ m) to avoid Bernhard vortex or settling separation caused by particle size differences.

Solvent volatilization equilibrium: Adjust the ratio of fast and slow solvents, control the volatilization gradient, and suppress uneven distribution caused by sudden increase in surface viscosity.

Film formation process control: Ensure uniform wet film thickness, sufficient flash evaporation time, gentle heating rate, and reduce local enrichment caused by convection.

2.  Solution

Starting from the formula materials can significantly reduce the occurrence of floating color and flower phenomenon. There are two conventional solutions for traditional anti floating color:
① continuously adjusting the ratio of multiple dispersants;
② Adding controlled flocculent dispersants with anti floating properties (such as Tech-504S), but none of these can meet the current demand for high-end industrial coatings. The performance differences compared to advanced block hyperdispersants are as follows:

     For high-end high gloss industrial topcoats, automotive repair paints, and high-end industrial paints, block super dispersants can reduce the occurrence of floating color and flower from the root, while providing good flocculation effect, better presenting the luster, color strength, and transparency of the pigment itself. Effectively avoiding the complexity and risks of traditional multi dispersant formulations。


3.  Product application data

     The market industrial coating block super dispersant is dominated by polyurethane structure, which has good dispersibility for carbon black and organic pigments. However, its performance in anti floating color of blended systems is weak, and it is suitable for blending and grinding polyamide dispersants. Its flocculation performance cannot meet the requirements of high-end industrial coatings at present.

     Tech-6320 is a new type of hyperdispersant developed by TAG Heuer based on block polymerization technology. Its molecular structure contains multiple pro pigment groups, anchored by a dual layer of low-level and charged groups. Combined with its special structure, it provides excellent steric hindrance and electrostatic effects, suitable for dispersing various pigments, with excellent compatibility and versatility, as well as anti floating and anti fading properties. The product parameters are as follows:

     In this experiment, commonly used block super dispersants were tested horizontally in the market. The experimental tests included 60 parts of hydroxypropyl resin, 10-14 parts of pigment, 6-8 parts of dispersant, and 100 parts of BAC solvent. After sanding to a fineness of ≤ 15 μ m, the paint was evaluated. The actual color display, color difference and gloss comparison effects are as follows:

●  MA100 carbon black system

●  F5RK Red System




●  15:3 Phthalocyanine Blue System



●  PG7 phthalocyanine green system



●  Eternal purple system

     In the horizontal comparison experiment of five pigments in the hydroxypropyl resin system, Tech-6320 showed significantly lower color difference compared to the reference group, lower viscosity, leading glossiness, and product advantages of 100% active ingredient, wide addition window, and excellent resin compatibility. It is particularly suitable for use in high-end industrial topcoats and other high appearance requirements scenarios.