The technology of aluminum pigments is still in continuous progress. Its current technical development focuses mainly on water-based and coating modification. In addition, it improves pigment fineness, shape regularity, particle size uniformity, product quality stability and other physical properties. Indicators, improvement of pigment dispersion and other properties, research and development of color aluminum pigments, special functional aluminum pigments, etc. are also its technological development trends.

   

    1. Water-based product (water-based aluminum pigment)

     

    Untreated aluminum pigments will chemically react with water to produce a large amount of hydrogen, which will destroy the metallic luster of aluminum particles, which will seriously affect their weather resistance. Therefore, the quality of water-based aluminum pigments and their application fields and production processes, especially coatings The process is closely related. The organically treated products have good water resistance, very low gas release and excellent weather resistance; the inorganically treated products have a thinner coating layer, which can effectively display the metallic luster of aluminum pigments. Water-based aluminum pigments are one of the inevitable development directions of the aluminum pigment industry. Although international companies have nearly 60 years of experience in this field, the research and development of new products has not stopped.

     

    2. Low pollution in production process

     

    In addition to water-based aluminum pigments, domestic companies also need to develop production processes towards low pollution. Many domestic enterprises used 200# solvent oil for grinding before 2009, and used high-boiling trimethylbenzene and tetramethylbenzene as the final solvent of aluminum silver paste. The aromatic hydrocarbons contained in these solvents are especially high-boiling trimethylbenzene and polycyclic tetramethylbenzene. Aromatic hydrocarbons are harmful to the human body and the EU has banned them by legislation. At present, most companies have adopted alkane solvents, such as high boiling point dearomatized hydrocarbon solvents D60, D70, and D80. However, the storage stability of aluminum pigment products and the compatibility of coatings still need to be improved, and a certain proportion of assistance is often required. Solvent.

   

    3. Colorization of aluminum pigments

     

    Another development trend of aluminum pigments is to form color effect aluminum pigments through surface coating modification. Color aluminum pigments not only have the original metallic luster of aluminum pigments, but also have bright colors. Because the color aluminum pigment has bright colors, strong corrosion resistance, good insulation, not easy to fade, and strong metallic luster, it has a wide range of application development prospects.

     

    In 2010, BASF launched a new generation of PaliocromBrilliantOrangeL2850 color aluminum pigments, which can display color effects from orange to red. The product uses SiO2 and iron oxide coated aluminum flakes, which contain 40% to 60% aluminum and 25% to 45%. Naphtha, 10% to 20% iron oxide and 1% to 5% silicon dioxide. The product has a good flashing effect and high hiding power, and is suitable for solvent-based and water-based systems. It is mainly used for high-performance automotive coatings and industrial coatings for consumer electronic products such as computers and mobile phones. It can also display more abundant effects together with other effect pigments. Color effect The coating process of SiO2 and organic pigments can improve the chargeability of aluminum pigments. Colored aluminum pigments are also suitable for powder coatings produced by the dry blending process, but they are not suitable for the current bonding process, because this process easily causes a large amount of colored pigments to detach from the surface of the aluminum particles, thereby causing the loss of specific optical properties.

     

    4. Special functional aluminum pigments

     

    It is the consensus of the industry to continuously expand the application fields of aluminum pigments. At the end of 2007, Aika launched an aluminum pigment for laser marking. Laser marking technology is one of the largest application areas of laser processing. It uses high-energy-density laser to locally irradiate the workpiece to vaporize the surface material or cause a chemical reaction of color change, thereby marking various characters, symbols and patterns. Aika’s Lasersafe040 aluminum pigment product is a pigment concentrate that can be used for thermoplastic polyolefins, such as PVC, PET, TPU, and polycarbonate. The addition amount is only 0.01%, which is very suitable for YAG laser (yttrium aluminum pomegranate). Stone laser) high-speed assembly line production, with high-contrast effect, can depict crystal-like patterns, text, and even photos in the plastic. Unlike other pigments used for laser marking, this pigment does not contain heavy metals, so it complies with FDA and European food safety standards and other regulations, and can be used in many fields such as food packaging.

   

    5. Nano aluminum pigment

     

    Nano-flaky aluminum pigments have attracted more and more attention in recent years. Their diameter and thickness are in the range of nanomaterials (30-50nm), so the diameter-to-thickness ratio is much larger than traditional aluminum powder. It has a very strong reflectivity to light and can be evenly distributed in the paint And it is almost horizontally distributed, and the protective and decorative effects produced are significantly better than traditional aluminum pigments. The current nano-flaky aluminum powder pigments mainly refer to the aluminum pigments (ie electroplated aluminum pigments) produced by the physical vapor deposition method (VMPs) process, such as evaporation-condensation method and sputtering-deposition method, while laser-induction heating method, Plasma heating method, electron beam radiation method and other nano aluminum powder production processes are still in the laboratory stage and have not been industrialized.

     

    6. Improve stability, dispersion and alignment

     

    The stability, dispersion and orientation properties of aluminum pigments are of great significance to their application effects. Aluminum is an active metal. In order to improve its stability, it is often necessary to use an inorganic layer or an organic layer for coating modification. The coated aluminum pigment can also improve the shear resistance performance and keep the shape of the scales from being damaged, which is particularly important in application fields such as powder coatings and plastics. In addition, the aluminum particles have a large specific surface area, and the aluminum particles without surface treatment are easy to agglomerate, and the coated aluminum pigment has better dispersibility.

     

    Finally, in terms of technology, Chinese aluminum pigment companies also need to strengthen the research on fatty acids and various additives used in the production of aluminum pigments to meet the requirements for the production of high-end aluminum pigments.