1. Dispersant

The surface of ordinary calcium carbonate is hydrophilic, it is not easy to disperse in the organic medium, the viscosity of the mixed system of it and the organic medium increases sharply with the increase of its content in the mixed system; The surface of calcium carbonate is lipophilic, it is easy to disperse in the organic medium, and the viscosity of the mixed system of it and the organic medium tends to increase greatly with the increase of its content in the mixed system. Since the surface of calcium carbonate is weakly alkaline, the carboxyl group of the organic acid has an affinity for the surface of calcium carbonate. In addition, because the hydrocarbon group of the organic acid has an affinity with the high polymer, the agglomeration phenomenon of the activated calcium carbonate is inhibited, so the calcium carbonate modified by the organic acid has better dispersibility in rubber and plastics.

2. Surfactant

Surfactant has hydrophilic group and lipophilic group, the hydrophilic group has affinity with calcium carbonate, and the lipophilic group has affinity with high polymer, when the surfactant is located between calcium carbonate and high polymer. Over time, the surfactant binds the calcium carbonate and rubber or plastic more tightly together through these two groups.

3. Silane coupling agent

Silane coupling agent is a low molecular compound. The coupling mechanism of silane coupling agent is mostly chemical bonding. After the calcium carbonate is modified by the silane coupling agent, a chemical covalent bond is formed between the calcium carbonate and the silane coupling agent, so that the calcium carbonate and the silane coupling agent are firmly bonded together. Therefore, through the bridge action of the coupling agent, the rubber molecules and the calcium carbonate molecules are closely connected, so the calcium carbonate modified by the silane coupling agent shows reinforcement.

4. Titanate coupling agent

Typical coupling agents are organic compounds containing silicon or metal atoms, and their molecules contain groups that can react with the surface of calcium carbonate to release hydrogen atoms, and also contain long bond groups with specific structures or functional groups such as double bonds.