Nano Calcium Carbonate: A Deep Dive into the Functional Filler Revolutionizing Multiple Industries
What is nano calcium carbonate?
Nano calcium carbonate is an inorganic filler characterized by a particle size range of 1 to 100 nanometers. Its ultrafine size and unique physicochemical properties make it an important material in numerous industries, including rubber, plastics, papermaking, inks, coatings, sealants, adhesives, pharmaceuticals, toothpaste, and food. It is worth noting that each application has specific requirements for key parameters of nano calcium carbonate, such as particle size distribution, crystal morphology, oil absorption value, and dispersion properties.
01 Application of Nano Calcium Carbonate in Plastic Products
In the plastics processing and manufacturing industry, traditional calcium carbonate is mainly used as a standard filler. In contrast, surface-modified nano calcium carbonate has a dual purpose; it can act not only as a filler but also as an activator and reinforcing agent. This material can increase the volume of plastic products, improve their hardness and mechanical strength, optimize processing performance, and improve key performance indicators such as heat resistance, flexural strength, and modulus of elasticity. Currently, nano calcium carbonate is widely used in the processing of various plastics, including PVC, PS, and PP, with the most widespread application in the PVC field. Especially in products such as wires, cables, and pipes, nano calcium carbonate exhibits excellent toughening and reinforcing properties. Its nanoscale characteristics endow PVC products with higher strength, barrier properties, flame retardancy, and thermal stability.
Among the various non-metallic mineral powder materials used in the plastics industry, calcium carbonate is the most widely used, accounting for approximately 60% to 70% of the total plastic additives. Despite its widespread application, many challenges remain in achieving high-performance applications. Key areas requiring further research include addressing the agglomeration problem of nano calcium carbonate, improving dispersion, and enhancing the bond strength of composite materials. These challenges also present opportunities for ongoing research and innovation.
02 Application of Nano Calcium Carbonate in Rubber
Nano calcium carbonate is mainly used in the rubber industry, such as in tires, wires and cables, and various rubber products. It increases the volume of rubber, reduces costs, and improves processing performance. Currently, the rubber industry primarily uses heavy calcium carbonate and standard light calcium carbonate, but the application range of nano calcium carbonate is continuously expanding. Compared to rubber products made with traditional calcium carbonate, rubber products with added nano calcium carbonate show significant improvements in elongation, compression set, yield strength, and tear strength. Furthermore, nano calcium carbonate, processed with a special technique, possesses high surface activity. Under ultraviolet light irradiation, it can release freely moving electrons, which readily react with oxygen or organic matter, effectively killing viruses and bacteria, thus giving it bactericidal and disinfectant properties.
Tires: In automobile tire production, nano calcium carbonate can partially replace carbon black and silica; however, its reinforcing properties still need improvement. Therefore, nano calcium carbonate is mainly used in low-stress areas, such as the sidewall, ply, airtight layer, inner layer, and buffer layer. Combining nano calcium carbonate with active zinc oxide during the production process can significantly improve the strength of the tire tread rubber.
Hose and Tape: In hoses and tapes, nano calcium carbonate can act as both a reinforcing agent and a whitening agent, and can also improve the dispersibility of adhesives.
Wires and Cables: Nano calcium carbonate is commonly used in protective sheaths for mining wires and cables, high-voltage wires and cables, marine wires and cables, as well as in adhesives for wires and cables.
Adding nano calcium carbonate to rubber compounds can significantly enhance their reinforcing effect and improve the material’s aging resistance, oil resistance, and dispersibility. While the reinforcing effect of nano calcium carbonate is superior to standard light calcium carbonate, its performance is still inferior to carbon black and silica. Completely replacing carbon black and silica with nano calcium carbonate may lead to a decrease in material strength. Furthermore, excessive use of nano calcium carbonate can cause roller sticking during processing. Therefore, the technical formulation must be carefully adjusted and continuously optimized.
03 Application of Nano Calcium Carbonate in Adhesives
Adhesives are mainly composed of base materials, curing agents, fillers, coupling agents, and catalysts. With the rapid development of China’s real estate, packaging, and building materials industries, the demand for adhesives has surged. Nano calcium carbonate, as a key filler, exhibits excellent compatibility and cost-effectiveness in adhesives. It can accelerate the crosslinking process, enhance thixotropy, and improve adhesion, tensile strength, and reinforcing properties. Currently, the application of nano calcium carbonate in polysiloxane sealants is relatively mature, but its application in polyurethane adhesives is still under development. Polyurethane adhesives are renowned for their excellent adhesion, aging resistance, and good surface coating properties, the latter often lacking in silicone adhesives. Furthermore, polyurethane adhesives also have significant advantages in applications requiring pollution-free, strong adhesion, and weather resistance.
Currently, many domestic enterprises are dedicated to the research and development of novel adhesives, including polyurethane adhesives and MS adhesives. Each system has its specific technical requirements for nano calcium carbonate. With in-depth research and technological maturity, nano calcium carbonate is expected to play an increasingly important role in the development of novel adhesives.
04 Application of Nano Calcium Carbonate in Coatings
Heavy calcium carbonate, light calcium carbonate, and nano calcium carbonate are all widely used in the coatings industry. Compared to heavy or standard light calcium carbonate, nano calcium carbonate offers superior reinforcing properties and enhances various coating characteristics, including hiding power, gloss, transparency, drying speed, and stability. In certain sectors, such as automotive and architectural coatings, nano calcium carbonate can partially or completely replace costly titanium dioxide, thereby significantly reducing costs for businesses.
Currently, domestically produced nano-calcium carbonate lags significantly behind imported products in terms of quality stability, with some of its better indicators often failing to persist or be maintained.
05 Application of Nano Calcium Carbonate in Inks
Ink is mainly composed of pigments, binders, fillers, and additives. Modified nano calcium carbonate exhibits excellent compatibility with binders and offers numerous advantages, including high gloss, high stability, and wide applicability, without adversely affecting ink performance or drying properties. This not only comprehensively improves ink quality but also reduces production costs.
In the ink industry, nano calcium carbonate plays a crucial role. The quality of ink directly affects the quality of printed materials. Inks formulated with nano calcium carbonate have a fine texture, good stability, excellent printability, and strong hiding power. Furthermore, they effectively absorb ink during the printing process, thus accelerating drying.
06 Application of Nano Calcium Carbonate in Papermaking
In the paper industry, nano calcium carbonate has the following key applications:
Paper Filler: Nano calcium carbonate, due to its small and uniform particle size, is a highly efficient filler that minimizes equipment wear and produces finer, more stable paper products. Its small particle size also helps improve oil absorption and increase specific surface area, thereby enhancing pigment adhesion. Furthermore, it exhibits excellent whiteness, high brightness, and good hiding power, thus improving the overall whiteness and hiding power of the paper. This not only reduces pulp consumption and costs but also contributes to environmental sustainability.
Cigarette Paper: The amount of nano calcium carbonate added to cigarette paper is typically 45% to 50%. This is mainly due to its high refractive index and good opacity, which effectively conceals the tobacco within the paper. During combustion, the carbon dioxide released by calcium carbonate helps regulate the burning rate without extinguishing the smoke. Furthermore, it helps retain ash content after combustion and enhances the paper’s permeability, thereby reducing the tar content in cigarettes.
High-Grade Toilet Paper Products:Nano calcium carbonate is widely used in high-end toilet paper products, especially in feminine hygiene products and baby products such as sanitary napkins and diapers. It is primarily used in the production of breathable and waterproof polyethylene films. Furthermore, the tiny particle size of nano calcium carbonate ensures that the final product is soft and skin-friendly, causing no discomfort.
Paper Coatings:In the paper coating industry, nano-calcium carbonate is typically supplied in slurry form, distinguishing it from traditional paper fillers. This method offers numerous advantages, including energy savings, reduced costs, dust-free production, environmental friendliness, and direct pumpability, thus simplifying the production process. Nano-calcium carbonate possesses high whiteness, a large specific surface area, high reactivity, and excellent reinforcing properties, significantly improving the gloss, whiteness, smoothness, surface strength, and ink absorption of coated paper.
Nano calcium carbonate has enormous potential for application in the papermaking industry. However, numerous technical challenges and application issues remain to be resolved, leading to the industry's current reliance on imported high-grade nano calcium carbonate products. With continuous advancements in papermaking technology, the industry is transitioning from acidic sizing to neutral and alkaline sizing, creating favorable conditions for the development of calcium carbonate applications. Therefore, the application of nano calcium carbonate is expected to become more widespread in the future.