A reactive alkoxy-siloxane resin used as binder that provides heat resistance and improves the physical performance of paints and coatings for high temperature resistance applications. The material can be moisture-cured at room temperature without the presence of tin catalyst.

Room Temperature Cure

High Heat Resistance

Water Resistance

Achieve Improved Flexibility in High-Temperature-Resistant, Room-Temperature-Curing Coatings

• Paint formulators are under pressure to deliver more-sustainable coatings. This is reflected in the demand for lower-temperature – and hence lower-energy – curing systems. This is especially relevant to formulators of high-temperature-resistant coatings, which usually require high curing temperatures.
• Traditional solutions have been methyl methoxy resins, but these suffer from stress due to their high-crosslink-density curing, which limits flexibility and film build.
• With DOWSIL™ 2405 Resin, formulators have an option to significantly extend the formulating space for room-temperature-curing, high-temperature-resistant coatings.

Features of DOWSIL 2405 Resin

• Room temperature curing without tin catalyst
• High heat resistance (i.e. 650°C with black and aluminum pigments) 
• Improved flexibility and impact resistance 
• Solventless delivery 
• Low smoke generation on initial heating 
• Compatible with pure methyl methoxy and traditional phenyl silicone resins

Room Temperature Cure

• When catalyzed with TnBT or other catalysts, DOWSIL 2405 Resin cures within 60 minutes at ambient temperature (20°C) to form a medium-hard coating.
• Some traditional phenyl resins, such as DOWSIL™ RSN-0806 Resin, physically dry to provide high hardness (Figure 1). However, they do not exhibit good cure, and they have little or no solvent resistance.
• In contrast, methyl methoxy resins, such as DOWSIL 2405 Resin, provide medium hardness but very good solvent resistance.

Improved Flexibility/Impact Resistance

• For selected substrates and where film thickness can be controlled, formulators can create very fast-curing systems using methyl methoxy resins such DOWSIL™ US-CF 2403 Resin. However, the high crosslink density associated with these resins can result in films that are brittle and have poor impact resistance, causing many formulators to avoid using them.
• With DOWSIL 2405 Resin, the cure rate is reduced slightly, but the flexibility and impact resistance are significantly improved (Figure 2). Formulators can blend DOWSIL 2405 Resin and DOWSIL US-CF 2403 Resin in any ratio to optimize some hardness and cure rate.

Figure 2. Flexibility Limitations of Room-Temperature-Curing Resin

Solventless Delivery with Good Build/Viscosity

• The very low molecular weight of methyl methoxy resins can lead to difficulties in the formulation of easy-to-spray products with good build per coat. However, with the slight increase in molecular weight of DOWSIL 2405 Resin, formulators have more formulation options to achieve good build with less risk of sags/runs.
• Plus, with its solventless delivery, DOWSIL 2405 Resin may be used for high-solids formulations (and low VOC).

Tin-Free Curing

• DOWSIL 2405 Resin is catalyzed by titanium compounds (such as TnBT) or other hydrolysis catalysts, and does not require the use of tin catalysts.

FEATURED RESOURCE

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DOWSIL 2405 Resin Product Information Sheet