Application of zinc phosphate
1, the application of zinc phosphate in coatings
Mainly used for anticorrosion, its body color is pure white, easy to color.
Principle: In the presence of water and oxygen, zinc phosphate can be combined with iron ions and ferrous ions to form a stable complex film, that is, the formation of Me (metal)2Zn2P2O5 compact passivation film, which can effectively isolate the internal metal and oxygen continue to react and oxidize, so as to achieve the effect of anti-corrosion. In addition, ammonium salt has a strong corrosion effect on metals, and zinc phosphate can inhibit the penetration and diffusion of ammonium ions on the film. The metal surface is "phosphatated" and remains dull. Phosphate group can inhibit the corrosion of metal by ammonium ion. Zinc ions form a negative level protection on the steel surface, preventing further corrosion of the metal.
Requirements: The particle size of zinc phosphate needs to be as small as possible, so that it can be evenly distributed in the paint, and effectively and evenly covered on the surface of the steel body, so that the surface of the steel body can better play the role of anti-rust and anti-corrosion.
Application advantages: Zinc phosphate primer non-toxic and pollution-free used to replace red lead, zinc chromium yellow and other traditional heavy metal anti-rust pigments, its anti-rust ability and traditional anti-rust pigments are better, its spatial structure can make it as a primer or middle paint has better impact resistance. Especially the modified zinc phosphate, because phosphate ions and zinc ions are more easily ionized, the anti-rust effect is basically the same as zinc chromium yellow. Among them, zinc phosphate epoxy has a better effect after taking part in zinc powder, which can increase the life of the paint body and the anti-rust effect is more obvious. Zinc-rich primer and epoxy zinc phosphate middle-layer paint are widely used in the construction of outdoor heavy anticorrosion and outdoor venues, such as the Three Gorges hydropower station, Qinshan nuclear Power plant, containers and so on.
Application field:
(1) As an epoxy zinc phosphate paint, it is suitable for use as an anti-rust primer on steel structures such as ports, docks, heavy machinery, mining machinery, grain machinery, electric machinery, chemical equipment, water conservancy projects, and steel structures above the waterline of ships.
(2), zinc phosphating solution; Mainly used for steel surface rust treatment rust process.
Principle: The liquid configured with zinc phosphate and phosphoric acid and surfactant can effectively dissolve iron oxides and release iron ions after steel contact, forming a dense complex protective film on the steel surface.
Application advantages: Zinc ion has high activity, can form a complex protective film with ferrous ion, and does not affect the painting of steel after treatment.
Application: Automobile, high-speed rail, ship, building external steel (cold rolled steel treatment)
(3), adhesive; It is mainly used as an adhesive for filling teeth
Principle: Powder, zinc oxide, solvent, zinc phosphate in accordance with the proportion of blending, the use of zinc phosphate non-toxic acid and alkali resistance low dissociation constant properties.
Application advantages: The obtained colloid has good mechanical strength, fast solidification, non-toxic.
Field of application: Medical dentistry
(4), used in electronic flame retardant material additives, low-temperature glass, high-grade transparent ceramics in the bonding and sintering additives.