Application Technology of Film Forming Aids in Architectural Coatings

Building coatings mainly use water as a dispersion medium and thinner, the advantage is that the dispersed medium of water is non-toxic harmless, manufacturing and storage without explosion risk, do not pollute the environment, to solve the problem of high temperature solvent-based coating VOC (volatile organic compounds).
In the role of coating film additives in water-based coatings
film additives are important components of building coating products, which can improve the production process, improve product performance, improve paint construction performance, reduce environmental pollution, the development of new paint special functions. Although the relative proportion of the vast majority of additives used in coatings is not high, but often to improve and improve the performance of coatings and coatings can play a very critical role, so more and more attention by the industry

.
film additives, also known as coagulants, polymerizers, usually high boiling point solvents, film additives act as a "temporary" plasticizer to reduce the glass temperature of the polymer (Tg), once the particle deformation and film process is completed, the film aid will evaporate from the coating film, so that the polymer Tg value is restored to the initial value. Typically, most film-forming additives are 1-2 hours behind water at room temperature, so film-forming additives should consist of solvents that are less volatile. The biggest prerequisite for film-forming additives is that during the drying process, moisture evaporates and the film-forming additive remains in the coating, which eventually evaporates itself from the coating. Latex commonly used in coatings has a lower glass transition temperature (Tg). Such as VAE emulsion at about 13 degrees C, therefore. In most temperatures above 5 degrees Celsius. These emulsions can be normal film- and membrane-forming additives, which play a role in accelerating the drying of the coating film. Figure 1 is the effect of glycol on the drying time of acrylic coatings when used as a membrane additive. With the increase of ethylene glycol doping, the drying time of the coating film is also reduced.
film-forming additives, in addition to contributing to film-forming properties, also have the function of reducing the freezing temperature of coatings. For example, ethylene glycol and propylene glycol can be used as antifreeze for coatings. In addition, film-forming additives have certain effects on the performance of coating wet film such as leveling, anti-flow and color display.
With the improvement of living standards, environmental protection requirements will increase, the demand for water-based paint additives will be higher and higher, so water-based coating film additives will become the development trend of the construction coatings industry.