Selection and recommendation of Evonik coating additives in high-solid formulations for vehicles

With voC regulations becoming more stringent, traditional solvent-based coatings are difficult to meet both emission and construction requirements.
Water-based coatings, powder coatings, UV coatings and high-solid coatings have obvious advantages in reducing VOC, especially high-solid coatings, which have the closest coating properties to traditional solvent-based coatings, making them one of the hot spots in coating research and development.
high-solid coating requires a high-solid, low-viscosity main resin, limited addition of solvents in the formulation, and many challenges

.
▪ Slow curing speed, it is difficult to adjust the drying speed with mixed solvents
▪ system surface pressure is higher and solubility is low, resulting in poor wetting, easy surface defects, affecting the flow level of these problems;
▪ high film thickness and harsh construction methods, such as airless spray or mixed air spray caused microblister problems
▪
In response to the difficulties and challenges faced by the above-mentioned high-solid coatings, Created Coating Additives offer a range of products such as dispersants, de-foaming agents, substrate moisturizers and leveling agents that can be applied to high-solid coatings to improve the appearance and performance of coatings.
of this topic, so it will be presented in the next two chapters. This article will focus on:
✔ dispersant selection
✔ defleant selection
01
dispersant selection
high solid content coating to meet VOC requirements, the amount of solvent added in the formula is very limited, if you do paint filler paint, you need dispersant with a strong anti-stick effect, so that the coating to maintain a low viscosity.
TEGO® Dispers 670 is ideal for high-solid-containing formulations with excellent adhesion, color display and pigment stability, as well as for organic pigments, inorganic pigments and carbon black pigments.
TEGO® Dispers 670 for titanium white powder Kronos 2310
with excellent adhesion reduction and very low yield
in other words, excellent fluidity and very low tentacleance
TEGO® Dispers 670 for carbon black
with excellent degiscosity and optimum viscosity stability
TEGO
The ® Dispers 670 is used for indigo blue
with excellent anti-adhesive effect and optimum viscosity stability
02
deblister selection
pain points for high solid-containing coatings




In addition, the addition of formula solvents is very limited, it is not possible to adjust the rate of drying through solvent volatilization rate, resulting in a high-solid coating
curing speed is
.
If you encounter some applications that can only be cured at room temperature
and cannot be forced to dry, the reaction foam problem of high-solid 2K-PU coating will be more prominent than traditional solvent-
based formulations
In this way, the anti-foaming agent is used to eliminate the reaction bubbles or spray caused by the micro-bubbles.
and high-solid coating formulation system because of the use of low molecular weight of the main resin, more sensitive to the compatible of desiccant, especially high-gloss paint, easy to affect visual aesthetics due to poor compatible reasons.
TEGO ® Airex 990 and TEGO® Airex 991 are desmoulation products specifically developed for high-solid coating systems.
can not only play a good balance between de-foaming strength and compatible, while the two products also have their own focus.
TEGO® Airex 990
High compatible
suitable for varnishes and paints
suitable for a wide range of spray applications
TEGO® Airex 991
De-foaming efficiency
for paint
especially for airless spray, mixed air spray and roll construction
TEGO® Airex 990 for high-solid 2K-PU varnish
excellent compatible
deblication while aiding leveling
also reduces the addition of leveling agents in formulations
TEGO® Airex 991 for high-solid 2K-PU finish
with excellent de-foaming performance