Licowax PE 520 is a low density polyethylene wax with branched chains synthesized at low pressure from Ziegler catalysts with an average molecular weight of approx. 2300. because of its good oxygen resistance and clean white appearance and the absence of fish eyes, Licowax PE 520 is an ideal carrier for color and functional masterbatches for polyolefins and as an external lubricant for polar plastics.
For the solvents and surfactants used in the coating, the higher the solid content of the coating, the more stable the secondary force association. Changes in temperature and shear force will affect the stability of the association. A formula with a higher water content will affect the stability of the association. Because the wax emulsion particles and the associative thickener are isolated from each other, the intermolecular network of secondary forces curls into a ball or causes the hydrophobic end of the thickener to turn inward, forming a flocculent gel bundle, which affects the associative effect.
Coagulation controls the amount of surfactant
In addition, the associative enhancement effect is generally formed by the secondary force network formed by the polar groups on the molecular chain. When a solvent or surfactant with appropriate polarity is added, it will shield the polar groups on the chain. Role, thereby destroying the node of secondary power and hindering the association. Therefore, a large amount of hydrophilic surfactants or diethylene glycol butyl ether solvents used in latex paint formulations will affect the thickening effect. In the medium and low PVC hydrophobic formulations, it is difficult to add pseudoplastic associative thickeners, or The dosage is small, which is not a sign of economic efficiency. It will only form false thickening, which will eventually lead to syneresis and delamination. Usually, associative thickeners are easy to produce due to the temperature sensitivity of surfactants and no yield value. The viscosity is not stable. At this time, a suitable thickener must be selected according to the actual situation. To ensure a uniform network, it is necessary to ensure that there is a sufficient amount of addition. Use Newtonian associative thickener, 0.8%~1.5% is a more reasonable dosage.
Hydrophobic coating formulation
The amphiphilic balance of water-resistant water-based coatings is the key to stable formulation. Storage and construction should be ensured to be oil-in-water. After construction, water evaporates and penetrates, and the emulsion quickly demulsifies and forms a film. At this time, water-in-oil may form, which will form fast drying and early water resistance in the exterior wall paint. This is helpful for the construction of the coating in the rainy season, and the PVC of the hydrophobic formula does not need to be too low, which can improve the hardness and stain resistance of the paint film. The air permeability of the coating film reduces the risk of blistering, and the overall hydrophobicity of the coating film improves the permeability resistance. Too low water content in hydrophobic coatings is also undesirable. It is recommended to control the non-volatile volume fraction per ton of paint between 40% and 45%.
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