What are the considerations in the application process of titanium dioxide
With its stable physical and chemical properties, titanium dioxide is widely used in coatings, plastics, paper, ink, pharmaceuticals, food and other fields.
钛白粉以其稳定的物理和化学性能广泛用于涂料、塑料、造纸、油墨、药品、食品等领域。
Color
颜色
Color is an important technical indicator of the marked pigment. The color indicator of titanium dioxide is whiteness. Even if it is the same chemical composition of titanium dioxide, due to the different process routes, raw materials, equipment, technology will produce different colors. Another factor that often plays a decisive role is its particle shape, size, particle size distribution, crystal shape, impurity content, etc.
颜色是标明颜料的重要技术指标。钛白粉的颜色指标就是白度。即使是同一化学成分的钛白粉,由于工艺路线、原料、设备、技术等的不同也会产生颜色上的不同。另外经常起决定性作用的因素是它的粒子形状、大小、粒度分布、晶型、杂质含量等。
Covering power
遮盖力
The optical nature of hiding power is caused by the difference in refractive index of the pigment and the medium around which it exists. Rutile titanium dioxide, with a refractive index of 2.71 and anatase 2.55, is the white pigment with the highest hiding power. The masking effect occurs mainly when scattering is caused by titanium dioxide, or when absorption is caused by the presence of colored substances in order to reduce the intensity of incident light. Therefore, the main reason for determining the hiding power of titanium dioxide is related to the particle shape, particle size and particle size distribution of titanium dioxide, in addition to the chemical composition and crystal type.
遮盖力的光学本质是颜料和存在其周围的介质的折射率之差造成的。金红石型钛白粉折射率为2.71、锐钛型为2.55,是遮盖力最高的白色颜料。遮盖效应主要是由于二氧化钛导致的散射,或者由于有色物质的存在而引起的吸收以使入射光强度减退时,就会出现遮盖现象。因此决定钛白粉的遮盖力的主要原因除化学成分、晶型外,还与钛白粉的粒子形状、粒径及粒度分布有关。
Coloring power
着色力
Coloring power is an important characteristic index of titanium dioxide, that is, after titanium dioxide is mixed with another pigment, it can get the ability of the mixture to show its own pigment. For white pigment, after it is mixed with a dark pigment, the lighter the color of the mixture, the stronger its coloring power.
着色力是二氧化钛的重要特性指标,就是二氧化钛与另一种颜料混合后,能够得到混合物显示它本身颜料的能力。对白色颜料而言,它与一深色颜料混合后,混合物的颜色越浅,表示它的着色力越强。
Oil absorption capacity
吸油量
Oil absorption is also one of the important pigment properties of titanium dioxide, as it relates to the filling state of the titanium dioxide in the spreading agent and can indicate its dispersion properties in the medium.
吸油量也是钛白粉的重要颜料性质之一,因为它涉及到钛白粉在展色剂中的填充状态,并能说明它在介质中的分散性能。
Light and weather resistance
耐光、耐候性
The light and weathering resistance of titanium dioxide is an important indicator to measure the application performance of titanium dioxide, and it is meaningless to refer to its light and weathering resistance alone. Only when the titanium dioxide is applied to relevant applications (such as paints, plastics, etc.) does this index become meaningful. Therefore, the light and weathering resistance of titanium dioxide refers to its light and weathering resistance in a certain field. In addition, the light and weathering resistance of titanium dioxide should be measured to ensure that the weathering resistance of its application carrier is better than that of titanium dioxide. The main factors affecting the weathering index of titanium dioxide are its chemical composition, the chemical form of the coating substance, the crystal structure, the application formula, etc.
钛白粉的耐光性和耐候性是衡量钛白粉应用性能的重要指标,单指其耐光性和耐候性没有意义。只有将钛白粉应用到相关的应用领域(如油漆、塑料等)后,此指标才具有意义。因此钛白粉的耐光性和耐候性是指其在某领域的耐光性和耐候性,此外衡量钛白粉的耐光性和耐候性要确保其应用载体的耐候性要优于钛白粉。影响钛白粉的耐候性指标的主要因素有其化学成分、包膜物质的化学形态、晶体结构、应用配方等。
Chemical composition factors
化学组成因素
The chemical composition of titanium dioxide determines the chemical properties of titanium dioxide, which is the main sign of mutual distinction between pigments. It not only reflects a series of pigment properties of the pigment, such as whiteness, achromatic power, oil absorption, etc., but also plays a great role in its application performance, such as weather resistance, dispersibility, etc.
钛白粉的化学成分决定了钛白粉的化学性质,它是颜料间相互区别的主要标志。它除了体现出颜料的一系列颜料性能,如白度、消色力、吸油量等外,对其应用性能作用也很大,如耐候性、分散性等。
Volatiles
挥发份
The volatile component of titanium dioxide is actually the water content. Because of the presence of high energy and hydroxyl groups on its surface, its surface always adsorbs a certain amount of water to reduce its surface energy, and the amount of adsorbed water is related to the surface organic treatment of titanium dioxide and the humidity and temperature of its storage environment. The volatility of titanium dioxide can not determine the merits of the product, depending on its application system. In general, for the water-based system, the volatile part of the high and low impact on the application is not significant, but for the oil-based system and polyolefin system, the lower the volatile part is required, the better.
钛白粉的挥发份实际就是水含量。因为其表面存在很高的能量和羟基,因此其表面总是要吸附一定的水分,来降低其表面能,吸附的水分量与钛白粉的表面有机处理及其存放周围环境的湿度和温度有关。钛白粉挥发份的高低不能判定产品的优劣,要视其应用体系而定。一般情况对于水性体系挥发份的高低对应用影响不大,但对于油性体系及聚烯烃等体系,就要求挥发份越低越好。
Dispersion
分散性
Dispersibility is also known as abrasive dispersion or abrasive wetting. When used in water as a medium, it is called water dispersibility, and when used in solvent and other coating systems, it is called oil dispersibility. Dispersibility index is an important application index of titanium dioxide. The good or bad dispersibility not only affects the titanium dioxide pigment's achromatic power, covering power, oil absorption, etc., but also affects the gloss and weathering resistance of the coating film or profile molding.When grinding and dispersing in the paint production plant, the goodness of dispersion directly affects the length of grinding and dispersing time, which is one of the important economic indicators in the production of paint. Moreover, if the grinding time is too long, it will increase the equipment pollution and make the product whiteness worse. In the production of plastic masterbatches or profiles, the good or bad dispersion directly affects the cycle of replacing the head screen and the performance of the final product.
分散性又称研磨分散性或研磨润湿性。在以水为介质中使用时则称为水分散性,在溶剂等涂料体系中使用时则称为油分散性。分散性指标是钛白粉重要的应用指标。分散性的好坏,不仅影响到钛白粉颜料的消色力、遮盖力、吸油量等,而且也影响涂料成膜或型材成型的光泽和耐候性。在涂料生产厂中研磨分散时,分散性的好坏直接影响研磨分散时间的长短,是涂料生产时的重要经济指标之一。而且研磨时间过长,还会增加设备污染,使产品白度变差。在塑料色母粒或型材生产中,分散性的好坏直接影响到更换机头筛网的周期及最终产品的性能。