2021-12-09 Pageview:1001
Licowax PE 520 is used in the plastics industry for the manufacture of color and functional masterbatches, and its use is increasing, especially in polyolefin masterbatches as a separate carrier or as a dispersant in certain proportions and to reduce the viscosity of the masterbatch.
Licowax PE 520 is perfectly suited for pigment masterbatches for the coloring of polyolefins. As a polyethylene wax, it is compatible with high-density and low-density polyethylene, as well as some polypropylene. Pigment masterbatches containing Licowax PE 520 have absolutely no influence on the mechanical properties of polyethylene.
The polymer emulsion particles are liquid repellent and will not be dissolved or swollen by continuous phase water. However, film forming aids with strong hydrophobicity, such as dodecyl ester alcohol, will be absorbed by the emulsion particles and swelled. In the hydrophilic formula, after the paint is applied to the wall, the film-forming aid will not be absorbed by the emulsion particles until the water volatilizes to a certain extent. At this time, the emulsion particles begin to aggregate, swell, deform, and form a film. The glycol solvents used in the formula are all co-solvents, which means that they can be dissolved in water to control freeze-thaw stability, drying speed, and edge setting. When water is contained, the co-solvent can help slow drying, but after the water and co-solvent volatilize, the film-forming assistant starts to swell the rubber particles. Therefore, the added amount of the film-forming aid will affect the viscosity and hardness of the emulsion film-forming material at this time. The film-forming aid is a true solvent, and only the co-solvent can help the water play the role of the continuous phase.
In relatively hydrophobic formulations, the phase inversion time of the emulsion must be controlled. As the PVC decreases, if the amount of water is controlled to prepare high-solid coatings, the increase in the amount of film-forming additives will increase the risk. Because when the hydrophobic substance is in a higher state, the emulsion used is an emulsion with strong hydrophobicity, the film-forming aid can easily enter the rubber particles and cause the rubber particles to swell in the coating storage, forming emulsion breakage.
If this phenomenon occurs during the storage period, it will cause the viscosity to rise, which will demulsify until it is scrapped. This is different from the floc gelation of inorganic substances, which thicken after gelatinization, and can also be degraded and used with water, but it is rough, the gloss and contrast ratio decrease, and the leveling becomes worse. This is also different from solvent-based paints. After swelling and gelation occurs, they can be ground and dispersed again, and then downgraded for use. The demulsification is irreversible, which leads to the scrap of the paint.
If the temperature is too high, the humidity is too low, or the water absorption of the substrate is too high during the construction, the drying speed of the paint film is too fast, and the wax for rubber particles produced by the demulsification may appear during the roller coating process, which will affect the coating. Membrane performance.
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