Calcium carbonate is an inorganic compound, which is the main component of limestone and calcite. White crystal or powder, tasteless, exposed in the air without reaction, insoluble in alcohol. According to the different production methods of calcium carbonate, calcium carbonate can be divided into heavy calcium carbonate, light calcium carbonate, colloidal calcium carbonate and crystalline calcium carbonate.
In coatings, calcium carbonate can be used as a white pigment, playing a role of skeleton. Calcium carbonate can be used as a physical pigment in coating industry. Because the color of calcium carbonate is white, compared with latex, the price of solvent in the coating is cheap, and the particles are fine, which can be evenly dispersed in the coating, so it is a mass used physical pigment. Due to the improvement of environmental awareness, a large number of water-based coatings have been used in construction. Because calcium carbonate is white, hydrophilic and cheap, it is widely used. Calcium carbonate can enhance the deposition and permeability of primer on the surface of base course.
In the coating, putty is used to fill the base surface, which is the middle layer of the whole coating. No matter what kind of putty, a large amount of filler is needed. The main body of filler in putty is heavy calcium carbonate, and a small amount of lithopone is added to increase the viscosity to prevent the coating from loosening. At the same time, precipitated calcium carbonate is added appropriately for polishing after drying.
In thick paint, calcium carbonate can thicken and thicken the paint, and play a role of filling and leveling. Therefore, heavy calcium carbonate and light calcium carbonate are usually added in the thick paint, and the addition of heavy calcium carbonate can reach 24.6% ~ 78.5%.
In the topcoat, that is, in the topcoat, the semi gloss and matt paint should adopt the method of increasing the physical pigment to reduce the gloss, and calcium carbonate is the ideal matting filler.