Yuan Lei's Little Knowledge | Application of Wet Mica Powder in Coatings
The ratio of the diameter to the thickness of the wet mica powder particles reaches 80-120 times, and the thickness of the wafer is only about tens of nanometers to one hundred nanometers. With high cover rate and UV absorption function, in the film can form an efficient barrier effect, so that corrosive substances in the film diffusion, penetration and migration become extremely circuitous, through the film time extended to 3 times, thus greatly improving the performance of anti-corrosion coatings.
Application in coatings
(1) Barrier function
Flaky filler in the film to form a basic parallel orientation, water and other corrosive substances on the film penetration is strongly blocked, in the case of the use of good mica powder, water and other corrosive substances through the film penetration time is generally extended by 3 times. Because the mica powder filler is much cheaper than the seed resin, it has very high technical value and economic value.
In short, the use of excellent mica powder is an important means to improve the quality and performance of anti-corrosion coatings and exterior wall coatings. During the coating process, the mica wafer is subjected to surface tension before the paint film is cured and lies down, automatically forming a structure parallel to each other and parallel to the surface of the paint film. Such a layer-by-layer arrangement, its orientation is just perpendicular to the direction in which corrosive substances penetrate the paint film, and the barrier effect is most fully exerted. If the mica wafer is perforated or torn, it will also seriously affect this barrier effect. The thinner the mica powder wafer, the larger the barrier area formed by the unit filler amount, and the moderate particle size, the better the effect
(2) Improve the physical and mechanical properties of the paint film
The use of wet mica powder can improve a series of physical and mechanical properties of paint films. The key is the morphological characteristics of the filler, that is, the diameter-thickness ratio of the flake filler and the length-diameter ratio of the fibrous filler. The particle-packed filler is like sand and gravel in the concrete, which plays a reinforcing role in the reinforcement.
(3) Improve the anti-wear performance of the paint film
The hardness of the resin itself is limited, and the strength of many fillers is not high. On the contrary, mica is one of the components of granite, and its hardness and mechanical strength are great. Therefore, adding mica powder as a filler in the coating, its anti-wear performance can be significantly improved. Automotive coatings, pavement coatings, mechanical anti-corrosion coatings, wall coatings and other preference for the use of mica powder, is also the truth.
(4) Insulation performance
Mica has an extremely high electrical resistance and is itself a good insulating material. The use of mica powder to improve the insulation properties of the paint film is a well-known technology, so I will not say much. It is very interesting that its compound with silicone resin or silicone boron resin is converted into a ceramic substance with good mechanical strength and insulation performance when exposed to high temperatures. Therefore, wires and cables made of such insulating materials, Even after burning in a fire, it still maintains its original insulation state. This is very important for mines, tunnels, special buildings, special facilities, etc.
(5) Flame retardant
Mica powder is a very valuable flame retardant filler, if combined with organic halogen flame retardant, can be made flame retardant and fire retardant coatings.
(6) anti ultraviolet, infrared performance
Mica has excellent shielding properties such as ultraviolet and infrared rays. Therefore, adding wet mica powder to outdoor coatings can greatly improve the anti-ultraviolet properties of the paint film and delay the aging of the paint film. Its infrared shielding properties are used in the preparation of thermal insulation, insulation materials.
(7) Reduction of settlement
The suspension performance of wet mica powder is very excellent, and very thin tiny wafers can be suspended in the medium for a long time without sedimentation and stratification. Therefore, when mica powder is used instead of the filler which is easy to settle, the storage stability of the coating is obviously improved.
(8) Thermal radiation and high temperature coatings
Mica has good infrared radiation ability, such as with iron oxide, can cause excellent heat radiation effect. The most typical example is the application in spacecraft coatings. Many heating of the original coating, as well as the coating of high temperature facilities, need to use a special coating containing mica powder. This kind of coating can work at extremely high temperatures, such as about 1000 ℃, when the steel is already red hot, but the coating is safe and sound.
(9) gloss effect
Mica has a good pearlescent luster, so when a large particle size flaky mica powder product is used, it can impart gloss, glitter or reflection to materials such as paints. On the contrary, very fine mica powder can cause repeated mutual reflection in the material, thereby producing a matting effect, and therefore a matting effect when using a small particle size mica powder product.
(10) Sound insulation and shock absorption
Mica can significantly change a series of physical moduli of the material, forming or changing the viscoelastic properties of the material. Such materials efficiently absorb vibrational energy and attenuate vibration and sound waves. In addition, vibration waves and sound waves form repeated reflections between mica wafers, which also weakens their energy. Therefore, wet mica powder is also used to prepare noise reduction, sound insulation, vibration reduction coatings.
In materials, mica powder, paint film, coating, function, filler, performance, mica, formation, use
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