A new generation of room temperature curing silicone resin is used in the field of high temperature resistance and corrosion protection

A new generation of room temperature curing silicone resin

Used in the field of high temperature resistance and corrosion resistance

Traditional silicone resin is a well-known resin structure, such as Evonik's SILIKOPHEN® P series, which has excellent corrosion resistance and can withstand high temperatures up to 650°C.

The new generation of silicone resin contains a large number of alkoxy functional groups, which can be combined with specific catalysts to undergo hydrolysis-condensation reaction at room temperature, so it is particularly suitable for room temperature curing and film formation, such as Evonik's SILIKOPHEN® AC series com" href="">coating online coatingol .

This new type of resin represents a new technology that enables it to be applied to large industrial components such as heat exchangers, distillation towers or industrial vessels.

01 Chemical structure of silicone resin cured at room temperature

Traditional silicone resins have methyl/phenyl functional groups and contain up to 95% siloxane in their skeletons.

Figure 1: Reaction mechanism of methyl/phenyl silicone resin curing at high temperature

The new room temperature curing silicone resin is different from the previous generation silicone resin, mainly due to its oligomer characteristics.

Table 1: Comparison of room temperature curing silicone resin (SILIKOPHEN® AC 1000 and AC 900) and high temperature curing silicone resin (SILIKOPHEN® P50/X and P80/X)

01 Hydrolysis reaction is carried out by moisture at room temperature

02 Condensation reaction

Figure 2 The reaction mechanism of methyl/phenyl silicone resin curing at room temperature

In order to achieve the polymerization of the resin through condensation and crosslinking, these functional groups first need to undergo a hydrolysis reaction to form a silanol group.

02 Performance characteristics of high heat-resistant anticorrosive coating formulation based on room temperature curing silicone resin

When the coating is fully cured, the silicone coating provides the following properties:

Coating performance

• Excellent anti-corrosion performance
  

• Excellent early chemical resistance (Figure 3)
  

• Permanent oxidation resistance and weather resistance
  

Thermal stability

• Excellent long-lasting high temperature resistance

• Maintain high hardness at high temperature (low thermoplasticity)

• Maintain excellent anti-yellowing performance at high temperatures
  

Both AC series silicone resins can be used to prepare high temperature resistant coatings.
However, they have certain differences in technology.

SILIKOPHEN® AC 900 has good pigment wettability and compatibility with other resins.
This kind of resin helps to prepare coatings with a certain degree of flexibility, and has a strong advantage in cold and hot cycle testing.

SILIKOPHEN® AC1000 has general wettability to the pigment, but the pigment has good stability under thermal stress, it is not easy to yellow, and it shows very low smoke when it is heated for the first time.

Figure 3 Xylene wiping high temperature resistant coating, based on high temperature curing (top) and room temperature curing (bottom)

03 Conclusion

Compared with traditional high temperature curing silicone resins, room temperature curing high temperature resistant silicone resins are a better choice.
Its high solid content and low viscosity can significantly reduce the VOC of the coating.

In addition, this resin also has the characteristics of low odor and low smoke.
When the formula is fully crosslinked and cured, the coating has excellent corrosion resistance, early chemical resistance, and long-term high temperature resistance.
These properties enable it to be used in chemical plants, power plants, waste incineration equipment, and other large-scale industrial facilities, and there is no need to stop production due to painting operations, thereby reducing costs.