Low-VOC water-based metal pigment anti-settling and orientation aid: modified ethylene-vinyl acetate copolymer emulsion

Lu Yuyan, Xu Jingtian, Li Yuxuan, Carlos Feito, Yang Lijun/Haimings
Water-based coatings have different viscosity requirements at different stages of application
Shear viscosity, production of the required low to medium shear viscosity, as well as the construction of medium to high shear viscosity, so that the coating has easy to operate, anti-flow hanging, anti-splash, anti-sinking and better paint film appearance and other applications. Sometimes a paint product needs to have different shear force segments at the same time with different effect requirements, as shown in Figure 1.
variables with different chemical structures and properties shown in Figure 2 can be used
in water-based coatings to meet different application performance needs

.
for several of these major fluidization aids, after adding the coating formulation, the effect of
on the application performance of the coating is seen in Table 1 by the regulation of pro/hydrophobic, structural and process.
And for water-based metal (aluminum powder and pearlew powder) pigment orientation, the current
is more common is the use of water-based polyamide fluidizers, but these additives are more suitable for paint and paint containing co-solvents. Limitations are in the use of coating systems that do not contain cosol solvents or low VOCs.
-modified ethylene-ethylene acetate co-polymer emulsion, because of its low VOC, easy to use
and also has a better anti-sinking and directional effect on water-based metal pigments and more and more widely used in water-based coatings.
Development background and product characteristics
All along, the development of water-based metal paint (aluminum powder and pearlescing powder) is limited to the arrangement effect of metal pigments
, through the design of the fluidizer so that it can have a low viscosity in the construction state of high shear force, and the viscosity after construction on the substrate can be quickly replied to, and make it viscous effect, continue its positioning of aluminum powder in the coating film, will not affect its effect. Solvent-based coating system has mature products, such as the use of EVA wax fluidizers and leveling agents to adjust, so as to obtain excellent metal pigment orientation, and because the solvent evaporation speed is faster, so the fluidity characteristics after spraying requirements are slightly lower. Water-based coatings, on the other hand, require more fluid properties and need to be optimized and strengthened in this part.
This novel product design concept is based on modified ethylene-ethylene acetate
co-polymer emulsion, providing particles with spatial resistance and co-ommersium with tactile behavior, improving the orientation effect of effect pigments such as aluminum powder or pearlescing powder in the coating, while reducing the subsidion of coatings in the production, transportation or storage process, suitable for water-based metal coating systems, such as automotive coatings, industrial coatings, wood and furniture coatings and leather coatings.
ideal aluminum powder positioning is reflected in the arrangement effect of the modified ethylene-ethylene acetate co-polypulator emulsion
, as shown in Figure 3.
added to the water-based coating formula, modified ethylene-ethylene acetate co-polymer milk
liquid has the following characteristics:
, better thickening tentacle performance

Paint film appearance
. Good anti-sinking and anti-flow hanging performance
This type of modified ethylene-ethylene acetate co-polyphur emulsion is easy to add, so that the
is recommended before use to stir evenly, and in the appropriate shear dispersion can be directly added, without the need to prepare pre-glue or pre-dilution. At the same time, it is recommended to add to the coating substation before aluminum powder or pearl powder. In addition, the system pH is recommended to be adjusted to 9.0-9.5 to ensure its best results, and the modified ethylene-ethylene acetate co-polypulation emulsion can also be used with other types of rheumourgents for better tentacles.
addition, the addition of modified ethylene-ethylene acetate co-polyphur emulsion can make the
coating have good viscosity recovery, as shown in Figure 4. Coatings in high shear spraying with low viscosity and atomization properties, coated to the substrate surface and then quickly return to low shear high viscosity, so that the coating has a good anti-sinking or positioning effect. The test results of Figure 4 also show that the product in this study has a better viscosity response in different additions. And the added amount is higher, the viscosity reply is also faster.
As shown in Figure 5, add a certain amount of modified ethylene-ethylene acetate co-ion
emulsion, so that the coating has a certain viscosity elasticity, particles in the fluid is not easy to sink and migrate, so that the coating has better storage stability. In addition, these particles of powder compounded by a special process, after drying the coating film, can make the flaky aluminum powder arrangement is equal, resulting in a better visual effect, as shown in Figure 6. In addition, the aluminum paint film Flop-index data also show that the modified ethylene-ethylene acetate co-polymer emulsion has better aluminum powder arrangement results, as shown in Figure 7.
, the addition of modified ethylene-ethylene acetate co-polymer emulsions can have
effect to improve the storage stability of water-like aluminum paint. As shown in Figure 8, the addition of modified ethylene-ethylene acetate co-polymer emulsion, whether it is a high viscosity finished paint, or a lower viscosity, have better anti-sinking properties.
In conclusion
towards water-based environmental protection, suitable for low VOC applications of aluminum powder orientation and anti-
sinking aids, has been through excellent technology preparation modified ethylene-ethylene acetate co-polyphur emulsion to achieve, the future coating fluid additive applications will be more comprehensive, all-water industrial coatings will be gradually expanded.
source: Haims PCI Can Be Named Culture