Clay desiccant, also known as montmorillonite. The appearance shape is grey small ball, which is most suitable for absorbing moisture in the environment below 50℃. When the temperature is higher than 50℃, the degree of water release of clay is greater than the degree of water absorption. However, the advantage of clay is the cheap price.
Polyether, alkyl-modified polydimethylsiloxane, when R is methyl, R3 is polyether chain, and R is alkyl chain (C2~Cio), it is polyether, alkyl-modified polydimethylsiloxane Oxane. The carbon number of the alkyl group will affect the surface tension of the product. The higher the carbon number, the greater the surface tension and the lower the slipping effect. Such products include BYK’s BYK-320.
Polyester-modified polydimethylsiloxane when R, R3 are methyl, and R3 is a polyester chain, it is polyester-modified polydimethylsiloxane. It has good compatibility with the coating base material. It has good stability and can be used in baking paint without thermal degradation. It can even be used in higher temperature but short time pre-coated coil coatings. Its representative products are BYK-310.
The thermal stability curve of polyester-modified (BYK-310) and polyether-modified wax (BYK-300) polydimethylsiloxane is the curve of residual amount changing with temperature at a certain heating rate.
Temperature/℃, it can be seen from Figure 13-1 that the polyester-modified polydimethylsiloxane BYK-310 is in general
The baking temperature is extremely stable, and the polyester chain starts to degrade when it exceeds 200℃.
Aralkyl modified polydimethylsiloxane when R and R are methyl and R is aralkyl, it is aralkyl modified polydimethylsiloxane to adapt to the compatibility of different coating materials need. And it has better high temperature resistance than polyester modified polydimethylsiloxane. Figure 13-2 shows the thermal stability of polyether-modified BYK-300, polyester-modified BYK-310, and aralkyl-modified BYK-322 at each temperature for 1 hour, expressed in terms of residual amount.
Aralkyl modified polydimethylsiloxane BYK —322 has the best thermal stability at higher temperatures.
ABYK -300 コ BYK -310 Ay BYK -322
The thermal stability of BYK—300, BYK—310, and BYK—322 at a constant temperature of 1h). The industry has summarized the above, in the modified polydimethylsiloxane structure, R is a methyl group, and R2 is a polyester chain or arane When R3 is an alkyl chain, the product shows better thermal stability.
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