Vatican What are the No Foam for paints(1)
dioxide
UV
Vatican Selection of antifoaming agents for different applications:
Flat coating
A substance that can reduce the surface tension of water, solution, suspension, etc., prevent the formation of foam, or reduce or eliminate the original foam. [1]
Defoaming agents should have the following properties: ① strong defoaming power and low dosage; ② Adding to the foaming system does not affect the basic properties of the system, i.e. does not react with the defoaming system; ③ Low surface tension; ④ Good balance with the surface; ⑤ Good heat resistance; ⑥ Good diffusion and permeability, high positive spreading coefficient; ⑦ Chemical stability, strong oxidation resistance; ⑧ Good gas solubility and permeability; ⑨ Low solubility in foaming solutions; ⑩ No physiological activity, high safety
Features: Low viscosity, low defoaming pressure
Explanation in reference book
An agent that promotes the uniform dispersion of material particles in the medium to form a stable suspension. Dispersants are generally divided into two categories: inorganic dispersants and organic dispersants. Commonly used inorganic dispersants include silicates (such as water glass) and alkali metal phosphates (such as sodium tripolyphosphate, sodium hexametaphosphate, and sodium pyrophosphate). Organic dispersants include triethylhexyl phosphoric acid, sodium dodecyl sulfate, methyl pentanol, cellulose derivatives, polyacrylamide, gum, fatty acid polyethylene glycol esters, etc.
hardening
Recommendation: Mineral oils or mineral oil modified polyethers
Leveling agents are generally divided into two categories. One type of leveling agent works by adjusting the viscosity and leveling time of the paint film. Most of these leveling agents are organic solvents or mixtures with high boiling points, such as isophorone, diacetone alcohol, Solvesso 150, etc; The other is to adjust the surface properties of the paint film to play a role, and generally speaking, leveling agents refer to this type of leveling agent. This type of leveling agent migrates to the surface of the paint film through limited compatibility, affecting surface properties such as interfacial tension of the paint film, and achieving good leveling of the paint film. Depending on the chemical structure, there are three main types of leveling agents: acrylic acids, organosilicon, and fluorocarbon compounds
titanium
agent
dispersant
dispersant
Elastic coating
Features: High viscosity, high No Foam pressure
Recommendation: Polyether modified silicone
Surface coating and film covering adhesive
Recommendation: Polyethers, which can effectively prevent surface defects and have a small impact on gloss
Water in Water Colorful
Features: More surfactants, stable foam
Vatican Recommendation: Use polyethers or mineral oil to modify polyethers
Precautions for use of paint No Foam:
Before use, stir thoroughly and mix evenly; Adding the paint while stirring; Before use, it is generally not diluted with water; The dosage should be appropriate. Excessive dosage can cause shrinkage, edge shrinkage, poor brushing performance, and other problems; Too little dosage leads to poor defoaming effect; Add it in two stages, namely, add it in the grinding stage and the paint mixing stage, generally accounting for half of the total amount each time. Use defoaming agents with good foam suppression effect in the grinding stage, and use defoaming agents with good foam breaking effect in the paint mixing stage