Nanoscale calcium carbonate

Nano calcium carbonate has excellent dispersion and transparency, excellent gloss, excellent ink absorbency and high dryness in ink products. Nano calcium carbonate is used as ink filler in resin ink. It has good stability and high gloss. It does not affect the drying performance of printing ink and has the advantages of strong adaptability and so on.
The paper industry is the most potential market for nano calcium carbonate. At present, nano calcium carbonate is also mainly used for special paper products, such as sanitary napkins for women and urine for babies. Nano activated calcium carbonate as paper filler has the following advantages: high lightness, high brightness, high brightness and whiteness of paper products; high expansibility can make paper mills use more fillers to greatly reduce the cost of raw materials; fine size, uniform, more uniform and smooth products, high oil absorption and can improve color paper Expected firmness.
Nano-CaCO3 as pigment filler in paint industry has the advantages of fine, uniform, high whiteness and good optical properties. Nanoscale superfine calcium carbonate has a space hindrance effect. In the paint, it can make the denser powder in the formula suspended to prevent settlement. After making the paint, the whiteness of the film is increased, the gloss is high, but the cover force is not reduced, which is mainly used in the high-grade car paint.
An industrial preparation method of nanometer activated calcium carbonate: this method is carbonated by adding carbon dioxide gas in a certain concentration of Ca (OH) 2 suspension. The nucleation rate of calcium carbonate nucleation is controlled by the temperature of Ca (OH) 2 suspension and the flow rate of carbon dioxide gas. After carbonization to a certain number of nuclei, the nucleation formation control is transformed into crystal growth control. At this time, the crystal growth rate is controlled by the addition of crystal regulator, thus the morphology can be controlled, and carbonization continues. The end point is added to the dispersant to adjust the dispersed cubic calcium carbonate nanoparticles on the surface charge, and then the dispersed cubic nano Calcium Carbonate Granules is treated with liquid surface bread. The nanoscale calcium carbonate particles can be controlled from 25 to 100nm, cubic shape, the specific surface is more than 25m2/g, the particle size distribution GSD is 1.57, the oil absorption value is less than 28g/100gCaCO3, and there is no aggregation phenomenon. The products obtained are excellent in performance and can be used as functional fillers in high-grade rubber, plastics and automotive primers.
The industrial preparation method of a nano active calcium carbonate consists of the following steps: (1) in the suspension of Ca (OH) 2, a gas containing CO2 is added into the suspension, carbonized to 5 ~ 40% carbonization rate, adding crystal regulator, continued carbonizing to pH to 8 ~ 9, adding surface charge and space steric regulator to continue carbonization to 6 to 7.5 of pH to generate nanoscale. A cubic meter of cubic calcium carbonate; one of the crystalline modifiers called phosphate, sulfate, acetate, citrate, monosaccharide, or polysaccharide, and its mixture of 0.05 to 3% of the weight of the slurry; the surface charge and the space resistance regulator are phosphate, sulfate, chloride and triethanolamine. One or more of twelve alkylbenzene sulfonates; the addition of surface charges and space steric regulators is 0.1 to 4% of the weight of CaCO3; (2) one or two species of fatty acids or water-soluble titanate coupling agents are prepared into aqueous solutions; the fatty acids are said to be C12 to C18 fatty acids; (3) the nano calcium carbonate slurry is used. The material is heated to 45~95 C, then the coating agent is added. The addition of the coating agent is 0.5 ~ 3.5% with the weight of calcium carbonate, and the coating time is 0.5 ~ 3.5. The size of the slurry is filtered and dried, that is, the nano active calcium carbonate is obtained.