Mica Powder for Paint

Applications of mica powder in ten functional paints

(1) Metallic insulation paint: if the main component is mica powder, the metallic insulation paint has good suspension property, spreadability, lubricity and adhesion. It also has a long service life. It can effectively improve the surface roughness of aluminum alloy castings.

(2) Anti-corrosion paint: if ultra-fine sericite powder is the filler of epoxy two-component anti-corrosion paint, partially replacing the expensive titanium dioxide in the same formula design, the chemical properties of the film remain unchanged, but the physical properties of the film will be improved, such as the adhesion, impact resistance, hardness and wear resistance.

(3) Fireproof paint: The sericite modified with 8% JSC coupling agent has better dispersibility. Compared with the fireproof paint without sericite, the performance of the fireproof paint with 12% sericite for steel structures is greatly improved. The heat resistance limit rises from 96℃ to 121℃. The water resistance limit rises from 28h to 47h. The bond strength rises from 0.45MPa to 1.44MPa.

(4) Heat-resistant paint: the heat resistance range of silicone-based heat-resistant paint is generally 200-400℃. If an appropriate amount of ultrafine mica powder is added, the substituent group of silicone resin will react with the OH group of mica powder, producing the silicate paint with moisture resistance, heat resistance (above 600℃) and radiation resistance.

(5) Functional architectural paint: the architectural paint with mica powder has better settleability, thixotropy and scrub resistance. With mica powder, the 107 water-based interior wall paint can meet the decorative requirements of interior walls of mid-range buildings, including the viscosity, consistency, covering power and whiteness.

(6) Antistatic paint: conductive mica powder is a new type of conductive filler. The flaky substrate contains natural mica powder. The surface consists of one or several layers of conductive substance. It has stable chemical properties, strong corrosion resistance and high conductivity. Conductive mica powder is widely used in antistatic paints, electromagnetic shielding paints, antistatic industrial floors and floor paints.

(7) Optical functional paint: mica powder is scaly. It has a strong ability to reflect ultraviolet light. It can be distributed in parallel to the surface and laminated in layers. It is widely applied paints to prevent radiation.

(8) Heavy anticorrosive paint: mica flakes are from a wide range of sources. They are cheap, and have excellent insulation performance, elasticity and flexibility. The diameter to thickness ratio is large, and the coefficient of thermal expansion is small. Mica flakes are inert in a variety of chemical media. They are also resistant to ultraviolet radiation. After surface treatment with coupling agents, mica flakes can completely replace expensive glass scales and stainless steel scales, thereby reducing costs. In addition, mica flakes range from 20 to 1,000 meshes. Mica powder have different specifications and grade ratios. They can improve the density of paint films, and reduce the permeability of paint films. They can effectively improve the water resistance and chemical corrosion resistance of water-based silicone acrylic latex paint films.

(9) Pearlescent paint: mica pearlescent pigments are widely applied in the paint industry. They are easy to evenly disperse in the base slurry of paint. They have excellent wettability and will not precipitate. More importantly, mica pearlescent pigmen can improve the physical and chemical properties of paints. They can enhance the chemical stability, covering power, lightening power, corrosion resistance, light resistance and weather resistance of paints. They can improve the mechanical strength and adhesion of paint films, to prevent cracking or falling off or penetration of ultraviolet light and water, thus extending the service life of objects.

(10) Aviation paint: mica is in a distinctive form, so it is widely applied in signs on aircraft skins. In addition, mica is easy to repair. It has good flexibility and self-adjustability in different environments.

At the engine nozzle of the aircraft tail, the temperature may be thousands of Celsius degrees . In addition to the extensive use of inorganic heat-resistant materials such as ceramics, heat-resistant insulation paints are indispensable. They are mostly inorganic polymer paints. For example, the ceramic-based thermal insulation paint is composed of mica sheets, silicon nitride and α-alumina. It is resistant to 1,900°C.

Mica powder can reduce the release of harmful volatiles from paint, and thus reduce the impact of paint on the environment and human body. The rise in environmental awareness had made the paint industry constantly seek more environmentally friendly solutions. Mica is natural, non-toxic and harmless, so mica powder is an ideal environmentally friendly additive in paint.

Mica powder has many benefits in environmentally friendly paint. First, mica powder is a kind of natural mineral. It contains no harmful substances and will not produce toxic gases, so the impact of paint on indoor air quality is fundamentally reduced. Secondly, mica powder can improve the durability and aging resistance of paint, and reduce the frequent replacement of paint and waste of resources.

In addition, mica powder can improve the covering power and adhesion of paint, reduce the need for repeated brushing, and save resources and energy. In the painting process, mica powder can form a uniform coating to reduce the waste of paint. In short, mica powder is environmentally friendly in paint. It provides a feasible solution to reduce the use of harmful chemicals and impact on the environment.

(1) Thickening problem

Granularity should be appropriate. For example, mica powder with a fineness of 400-800 meshes is suitable for general-purpose exterior wall engineering paint. If mica powder of 1,500 meshes or finer is used, a problem of thickening may occur.

Too much sericite may be difficult to disperse, resulting in thickening. For example, the proportion of sericite should be 2.5% to 5% in general-purpose exterior wall engineering paint. If the proportion is 10%, a problem of thickening may occur.

(2) Extinction problem

Due to the flaky structure, the extinction of mica powder is inevitable. We should choose products of large particle sizes. It is recommended to reduce the amount of mica or avoid using mica in high-sheen paint. But mica is recommended in matte, semi-bright, dark and other systems.

Mica powder can improve the sheen or paint. Pay attention to the following in the application:

1. The flatness of mica powder affects the sheen of the paint film. Poor flatness of the mica powder surface will reduce the surface sheen of the paint film, and even lead to sagging, fisheye or other defects.
2. The amount of mica powder affects the sheen or paint. Mica powder within a certain range can improve the sheen of paint. Too much mica powder will have reverse effects and even cause light color or sagging.
3. The particle size distribution of mica powder affects the sheen of paint. In general, when the fineness of mica powder increases, the sheen of paint will be improved.

Under normal circumstances, mica in paint is not harmful to the human body. Mica is composed of a variety of chemical components, including silicate, iron, magnesium, aluminum and sodium. These components are not enough to do harm to the human body. In case of inhalation or swallowing of a lot of mica, however, respiratory and digestive systems may be injured. In addition, mica dust may cause the skin or eye irritation.

In order to ensure safety, paint containing mica should comply with relevant standards. Manufacturers should ensure that the content of mica in their products does not exceed the value in safety standards. It is necessary to wear protective gloves, masks, goggles and other protective equipment to handle paint, to avoid inhalation of mica dust and contact with the skin.