Typical characteristics of water-based system wetting agent dh-405

Typical characteristics
Appearance: Light yellow to colorless transparent liquid
Activity, wt%: >;99
Density (25℃): 1.022
Water solubility: soluble in water, polar organic solvents, alcohols, ethers, etc.
Ionicity: non-ionic
ph value (1% aqueous solution): 6～8
Freezing point: ≤0℃
Flash point: >100℃

Defoamer
Some foreign companies also call it an air release agent. The deaerator is mainly aimed at single small bubbles in high-viscosity solvent-based paints, which are difficult to rise to the liquid level and be eliminated. Defoamers can tives. The foam breaker invades the foam film through the action of surface tension, disperses and replaces the foam film layer, and the film layer becomes thinner, and then is strongly drawn by the surrounding film layer with high surface tension, causing the foam that has been generated to burst, as shown in Figure 3- 7 shown [20.22]
Table 3-5 The defoaming effect and E and S values ​​of some defoamers

Defoamer
honeywell oxidized polyethylene wax
Optimal concentration
Prevent foaming degree/%
Improve the flow of air in the paint, so that the adjacent foams gather and merge with each other, the volume becomes larger, and the speed of movement to the surface is accelerated, so that it is easy to break.

Defoaming effect of deaerator
(a) The defoaming agent is replaced at the gas-liquid interface;
(b) Adjacent bubbles merge;
(e) The bubble becomes larger and the rising speed is accelerated;
(d) The bubble rises to the surface and air is released.

Obviously, the mechanism of action of the above three kinds of defoamers for coatings will help us to understand and understand the entire defoaming process, but for a specific defoamer, its defoaming effect must be clearly defined as a certain mechanism. Is impossible. As mentioned above, foam inhibitors are always used in coatings in most cases.