Variety Feature Application Traditional surfactants (mainly anionic or nonionic) Poor water resistance Easy to foam and stabilize foam cheap price Putty and low-grade system · Fluorocarbon polymer Efficient Reduce static surface tension Good effect on contaminated substrates Easy to cause surface problems Not easy to control High price Very difficult to attach substrates And contaminated substrates PSAMS Wetting effect、Good resistance to foaming, shrinkage and water resistance Wide adaptability Common application Non-silicon non-fluorine Minimize possible defects Minimize possible defects Low water sensitivity Low foaming Good dynamic effect expensive All kinds of coating The ideal wetting agent should contain the following aspects: 1. Effectively reduce the surface tension of the system and improve its wettability and permeability to the substrate. 2. Foaming and foam stabilization as low as possible. 3. As low a water sensitivity as possible. 4. Does not affect interlayer adhesion 5. A good balance of surface tension can improve the wetting of the substrate without affecting the leveling or defects due to excessive reduction of surface tension. Generally, the dosage of levelling agent is 0.1%~1.0%, and it is better to control it at 0.3%. When the defoaming agent exceeds the quantity, in order to overcome shrinkage cavity, the dosage of levelling agent can even exceed 1% in the putty formula without levelling agent . Sinograce Chemical produces water based additives, such as thickener, crosslinking agent, wetting agent.

Formulation design system for water based coatings - wetting leveling agent The wetting leveling agent can effectively reduce the surface tension of the system and significantly improve the construction effect of the waterborne wood lacquer.After the addition of the wetting leveling agent, the wetting property and permeability of the paint increase, the leveling property of the paint liquid is improved, and sometimes the shrinkage (frame effect) problem can be overcome.More importantly, the leveling agent can solve the common shrinkage cavity problem, especially the shrinkage cavity caused by excessive use of the defoaming agent.Excessive leveling agent will offset the defoaming effect of the defoaming agent, so that the paint liquid will generate bubbles during construction, and some will have obvious foam stabilization effect. Therefore, it should be used with good leveling property, low foaming property and stable foaming. Small wet wetting leveling agent.The combination of leveling agent and defoamer, including the selection of varieties and the control of dosage, is the focus of research on waterborne wood lacquer formulations.

Types of defoaming agents Character Application Mineral oil Strong anti-bubble ability Low price Poor system compatibility Easy migration Primer Matte Organic silicon class Strong defoaming ability higher price Different product performance differences Large adjustment space Improper selection can cause film defects Influence gloss, flow equality Various coatings Non-silicone non-oil Good security Low probability of defects Does not affect the gloss But the amount is slightly larger Insufficient bubble breaking ability higher cost Various types of coatings, especially in high gloss finishes There are many defoamers on the market, and the choices are very cautious and can be noted in several ways: 1. Controlled compatibility, that is, to achieve the balance between defoaming and surface effects, both defoaming and prevention of defects such as shrinkage cavities and poor leveling. 2. Defoaming according to the construction conditions and methods, such as brushing, spraying and roller coating, face different degrees of foaming, and also means different defoaming agents. 3. The balance between foam suppression and foam breaking can be reasonably matched according to different processing and construction methods. 4. Long-term defoaming performance. Many defoamers will gradually reduce their defoaming performance during storage of the paint, and the antifoaming agent content in the paint should be higher when designing the formula. The amount of defoaming agent is 0.05% to 0.5% of the whole formulation, preferably about 0.1%. If the defoaming agent used exceeds 0.5% to have a good defoaming effect, the defoaming agent should be considered.Different resin systems are sensitive to defoamers. The type and amount of aqueous defoamer selected must be determined experimentally, depending on the system.

Defoamer is one of the most difficult additives in waterborne wood coatings to control the balance between defoaming and leveling.The paint liquid will generate bubbles during the application due to agitation .If the bubbles present in the paint are not removed in time, the film will dry and form an unacceptable flaw.The paint also produces air bubbles during production, pumping and filling. Defoaming is a non-negligible factor in the formulation design process. The defoaming mechanism of the defoaming agent is to penetrate the foam film produced by the system by wetting and continuously spread on the film, so that the surface tension of the foam film is unbalanced and broken bubble.Generally speaking, the defoaming agent is divided into two types, a suds suppressor and a defoaming agent. The function of the suds suppressor is to inhibit the foaming of the waterborne wood coating under the action of an external force, and the defoaming agent is mainly on the surface of the foamed film. Rapidly spread, destroy the elastic membrane of the bubble, and make it rupture, but often the effect of the two combinations is better, otherwise at least one effective defoamer should be selected.Most antifoaming agents, especially silicone defoamers, will cause shrinkage of the wet paint film when the dosage is too large. Therefore, the amount of defoaming agent can be basically eliminated by the principle of eliminating bubbles, so that the defoaming effect cannot be excessively pursued. Side effects such as shrinkage holes. For waterborne wood lacquers, mineral oil defoamers are more tolerant than silicone defoamers, and adding a little more is not prone to severe shrinkage, which can be preferred. Sinograce Chemical produces water based additives, such as thickener, crosslinking agent, wetting agent.