Calcium carbonate is the most widely used body pigment in coatings. It is not only cheap, can greatly reduce the production cost of the coating, as one of the functional filler, it can affect many properties of the coating, such as changing the mechanical strength of the coating film, improve the coating water resistance, some data also introduced that it has resistance to powder, etc..It is its as high quality and cheap functional filler, so in civil and industrial coating, it has been one of the most important basic materials in the composition of coating.
Ground Calcium Carbonate
Ground calcium carbonate is the world's first filler in the coating industry, China's current coating with ground calcium estimated amount of more than 400,000 t, in which construction paint, paper paint, powder paint is the most ground calcium consumption of the field. Because the site of ground calcium application of most of the fineness of the requirements is not very harsh, so the current market of ground calcium generally did not go through the surface treatment. But powder coating due to poor fluidity, generally should be superfine ground calcium carbonate surface modification, modification agent mostly using some coupling agent such as titanate, or phosphoric acid, surfactant, aluminum sulfate and sodium hexametaphosphate, sometimes fatty acids are considered together, some recent use of high polymer as surface treatment agent. Through modification, the dosage of calcium carbonate can be increased by 20% ~ 50%, and the luster and leveling property are increased. Because the qualitative of ground calcium carbonate is avirulent, there is market base very much in the powder coating that asks avirulent, like baby car, toy, etc.
the primer and putty polishing, gloss finish. However, the chemical resistance, lightness, gloss, leveling, hardness and color stability (the effect of weather resistance) of the coating were improved after the use of microne ground calcium carbonate in the topcoat.
The application of wollastonite in the paper industry can replace part of the wood pulp, which is an important application direction in the paper production process. When the added amount of wollastonite continues to increase, the physical strength of the finished paper will also show a downward trend. If the added amount is 35%, the strength of the finished paper can meet the needs of general use. For example, wollastonite and plant fiber can be used to make composite paper. When the added amount of wollastonite is controlled at 30%-40%, the folding resistance and tear index of the finished paper can be compared with those with 20% calcium carbonate filler. The paper is consistent. To a large extent, it can save the amount of plant fiber added, indirectly reduce the felling and utilization of forest resources, and have the effect of reducing production costs and maintaining ecological balance.