SiO2 Silicon Dioxide Powder For Coil Coating

What is the role of silica Matting Agent in solvent coatings?

The more commonly used matting agents are divided into two categories: organic and inorganic: Inorganic matting agents

are mainly silica matting agents, whose chemical composition is ultrafine sio2, and can be divided into two types of surfaces:

organic treated and untreated. Now we mainly discuss the application of silica matting agents in coatings. Pigments or fillers

are added to the coating and evenly distributed in the coating film to produce a slightly rough surface. Light calcium carbonate

or talcum powder is used to produce matte coatings. The dosage is large, often exceeding the critical pigment volume

concentration of the coating, making the coating physical properties poor, such as stratification and hard precipitation. The use

of matting powder can avoid the larger the surface particles, the greater the micro-roughness, and the lower the gloss.

Silica matting powder matting mechanism: The varnish film without matting agent is in a mirror film flat state. When light reaches

the mirror film surface, part of the incident light is absorbed, part is reflected, and part of the reflection makes the film shiny. The

paint film containing silica matting agent is evenly distributed in the paint film to produce a slightly rough surface.

From the scanning electron microscope photos of the coating cross section, it can be clearly seen that the matte particles are evenly

distributed in the coating. When the incident light reaches the uneven surface of the paint film, diffuse reflection will occur, that is,

scattering will produce a low-gloss matte and matte appearance. High porosity. Good particle size distribution and suitable surface

treatment of silica matting agent can achieve good matte effect.

Silica matting powder: The powder made by grinding natural SIO2 has a high impurity content. The main component is SIO2, which cannot

be called silica and has no matte properties. It can only be used in coatings as a filler and has no matte effect. Silica matting agent mainly

generates SIO2 as a coating, which is divided into Fumed Silica and precipitated silica. Its microstructure is amorphous or glassy.

The silica system generated by the precipitation method is mainly made of quartz sand and undergoes a high-temperature melting reaction with

sodium hydroxide or sodium carbonate in a kiln. Compared with natural silica, silica has high silica purity. It is highly inert. It is resistant to ultraviolet

rays. The refractive index of amorphous silica is 1.46, which is close to the refractive index of many epoxy resins in the coatings industry. Therefore,

amorphous silica can be used as a matting agent for coatings with excellent optical properties.

Tips: 

* Before you use it, please test and make sure the dosage before using according different formulations and conditions.

* Recommended dosage is 3% -5%.

Anticorrosion Pigments, Inkjet Receptive Coating, Matting Agent