What is silicone?
Silicon, the scientific name is generally called siloxane or polysiloxane. The silicone powder used in the market is generally produced by adding higher molecular weight organic silicone and silica, which means dispersing siloxane into 2 Among silicon oxides, low molecular weight silicone is generally liquid, commonly known as silicone oil. But if the molecular weight is large enough, it can be made into a solid sheet.
Silicone powder and silicone masterbatch
What is silicone masterbatch? What is silicone powder? In fact, it is very simple to distinguish. Ultra-high molar mass polysiloxane is uniformly dispersed in particles or loaded on the surface of silica powder. The former is called silicone masterbatch, while the latter is called silicone powder.
Generally, silicone powder is classified according to the amount of silicone content. If the content of silicone in your silicone powder is 40%, that is, the silicone powder should be 40% silicone (silicone oil). +60% silica and other additives (such as coupling agents, etc.). If the silicone content is relatively high, it is best to make a masterbatch first, because the intermolecular force of siloxane is strong and it is not easy to pass through physical methods. Even dispersion requires strong shearing to complete. The higher the siloxane content in silicone powder, the greater the viscosity of the material and the less likely it is to disperse when used in plastics. When the content and molecular weight of silicone is high, it can be used as a wear-resistant agent, but its lubricating performance is reversed. The mechanism of lubrication is that the friction coefficient between silicone and silicone is small, and the silicone is stably and evenly dispersed. This phenomenon only occurs in the system. If it cannot be dispersed in the system, it cannot be said to be lubricated.
The so-called silicone masterbatch is diluted silicone (usually silicone + silica) and then 50%-30% of a carrier and other additives. The carrier is usually polyolefin, which can be directly Added as a sizing agent for inorganic fillers.
Silicone masterbatch has excellent properties when used in plastics:
1. Improve plastic processing fluidity and demoulding properties. Reduces torque, reduces equipment wear, makes mold filling easier, and reduces product defective rates;
2. Significantly reduce the friction coefficient, improve slipperiness, improve surface gloss, enhance surface silky touch, and improve scratch resistance;
3. Improve flame retardancy, reduce smoke density, and improve impact strength and surface gloss of flame retardant materials (high filling);
4. Good stability and non-migration;
5. Silicone masterbatch is safe to use, easy to mix, stable in performance, and easily dispersed in resin;
6. Different addition amounts have a direct impact on performance. Generally, when the addition amount is low, the fluidity and internal smoothness of the plastic will be improved, making molding easier. When added in high amounts, the surface properties of the material will be improved, including reducing the friction coefficient and imparting gloss to the surface.
In some special fields, silicone masterbatch has very good results:
1. In halogen-free flame-retardant wire and cable materials, the scratch resistance and frost blooming can be significantly improved.
2. In automotive PP composite materials, the scratch resistance and surface gloss of the material can be significantly improved.
