Application of calcium carbonate in rubber_Industrial additives

Calcium carbonate, commonly known as “industrial MSG”, is one of the commonly used fillers in various industries. According to different production processes, calcium carbonate is divided into heavy calcium carbonate and light calcium carbonate.

Heavy calcium carbonate (commonly known as heavy calcium) can be produced by directly crushing natural calcite, limestone, chalk, shells, etc. using mechanical methods (using Raymond mill or other high-pressure mills). Since the settling volume of heavy calcium carbonate is smaller than that of light calcium carbonate, it is called heavy calcium carbonate.

Light calcium carbonate, also known as precipitated calcium carbonate, or light calcium for short, is made by calcining raw materials such as limestone to produce lime (the main component is calcium oxide) and carbon dioxide, and then adding water to digest the lime to produce lime milk (the main component is Calcium hydroxide), and then carbon dioxide is added to carbonize the lime milk to form calcium carbonate precipitation, which is finally obtained by dehydration, drying and crushing. Or first use sodium carbonate and calcium chloride to perform a metathesis reaction to generate calcium carbonate precipitate, and then dehydrate, dry carbonate and pulverize it to obtain it. Since the sedimentation volume of light calcium carbonate (2.4-2.8mL/g) is larger than that of heavy calcium carbonate (1.1-1.9mg/L), it is called light calcium carbonate.

Calcium carbonate is one of the main filling and reinforcing agents used in the rubber industry. In order to meet the diverse needs of the rubber industry, light calcium and heavy calcium are widely used in the rubber industry.

Application of calcium carbonate in rubber Application of calcium carbonate in rubber

Heavy calcium carbonate is mainly used as a filler in the rubber industry and also Can be used as a colorant, release agent and release agent. Heavy calcium carbonate has good mixing performance with rubber, can increase the stiffness of the rubber compound, does not delay vulcanization, and is cheap. It is suitable for heels, soles, floors, hoses, and molded, extruded and foamed rubber THF products. wait.

Light calcium carbonate has semi-reinforcing properties and is mainly used as a white reinforcing filler for rubber. Light calcium carbonate is easily dispersed in the rubber compound and can improve the tensile strength, tear strength and wear resistance of the rubber compound. Its physical properties are slightly better than those of heavy calcium carbonate rubber compound. Light calcium carbonate is widely used in rubber products and is often used in conveyor belts, hoses, rubber sheets, tapes, rubber shoes and medical rubber products.

Ultra-fine activated calcium carbonate has extremely small particle size and high activity, so its reinforcing properties are much better than light calcium carbonate and equivalent to precipitation method silica, but ultra-fine activated calcium carbonate is mixed It generates a lot of heat and the rubber vulcanizes quickly. Ultrafine activated calcium carbonate is often used together with other reinforcing agents for tire buffer rubber and inner tubes, bicycle inner tubes and outer tires, transmission belts, hoses, rubber shoes and tape rubber products.

Application of calcium carbonate in rubber Technical index requirements for calcium carbonate used in the rubber industry

Heavy calcium carbonate used in the rubber industry can be divided into technical indexes Six models: Type I 2000 mesh, Type II 1500 mesh, Type III 1000 mesh, Type IV 800 mesh, Type V 600 mesh, and Type VI mesh.