Overview
Desmodur BL 3175 SN is a blocked HDI polyisocyanate hardener used in colorfast and weather-stable, one-component polyurethane stoving coatings. As one of the recommended international brand products in our auxiliary agent range, this hardener is supplied with supply chain resource support for coating formulators sourcing blocked isocyanate systems for industrial and automotive finishing.
Key Properties of Desmodur BL 3175 SN
- Blocked HDI polyisocyanate hardener for one-component (1K) PU stoving coatings
- Supports colorfast and weather-stable finished coatings
- Compatible with a range of Desmophen polyols under equivalent crosslinking conditions
- Stoving temperature can be reduced with a suitable catalyst without reducing storage stability
Solubility and Thinning Guidance
This hardener generally shows good compatibility with the solvents listed on its technical data sheet; however, the solutions formed must always be tested for storage stability before use. It can be thinned to a solids content of 40% by weight with ketones, esters, ether esters, and aromatics. It can be thinned further, to a solids content of 60% by weight, with mixtures of higher-boiling aromatics such as solvent naphtha 100 and 150. Aliphatic hydrocarbons cannot be used as solvents for this hardener.
Because a blocked isocyanate only becomes reactive once the blocking group is thermally released during stoving, solvent choice and thinning ratio mainly affect application viscosity and film build rather than pot life, which is one of the practical advantages of one-component stoving systems over conventional two-component polyurethane coatings.
Compatibility with Polyols and Plasticizers
Given equivalent crosslinking (NCO/OH = 1.0), this hardener is generally compatible with Desmophen 651, 670, 680, 690, RD 181, A 160, various polyacrylates, and Desmophen T 1665. It can also be combined with various plasticizers, including phosphoric acid, sulphonic acid, adipic acid, and phthalic acid esters. As with any new combination, formulators should always test compatibility before committing to a production formulation, since polyol selection has a direct effect on final film hardness, flexibility, and chemical resistance in the cured coating.
Applications
This hardener can be used as the hardener in colorfast and weather-stable, one-component polyurethane coatings. The stoving temperature can be significantly reduced by adding a catalyst, such as dibutyltin dilaurate (DBTL), without reducing storage stability. The product is used in high-grade industrial finishes, including:
- Electrical appliances and small components
- Can coatings and coil coatings
- Primer surfacers and topcoats for automotive finishing
This hardener can also be used as an additive in conventional stoving systems to improve flexibility and adhesion. These applications align with our Electrical & Electronics and Automotive & Transportation industry categories.
Where to Source This Product
Thousands Chemicals connects industrial finishers, coil and can coating formulators, and automotive coating manufacturers with Desmodur BL 3175 SN and related auxiliary agent products through our digital B2B marketplace. Coating hardness, gloss, and weathering performance are commonly evaluated using test methods published by organizations such as ASTM International. Our team can help confirm packaging, lead times, and technical documentation for your target application and order volume.
FAQ
What is Desmodur BL 3175 SN used for?
It is a blocked HDI polyisocyanate hardener used in colorfast, weather-stable one-component PU stoving coatings, including electrical appliances, can and coil coatings, and automotive primer surfacers and topcoats.
Which solvents can be used to thin this hardener?
Ketones, esters, ether esters, and aromatics can thin it to 40% solids content, while higher-boiling aromatics such as solvent naphtha 100 and 150 can thin it to 60% solids. Aliphatic hydrocarbons are not suitable.
Which polyols is this hardener compatible with?
At equivalent crosslinking (NCO/OH = 1.0), it is generally compatible with Desmophen 651, 670, 680, 690, RD 181, A 160, various polyacrylates, and Desmophen T 1665, subject to compatibility testing.
Can stoving temperature be reduced with this hardener?
Yes, adding a catalyst such as dibutyltin dilaurate (DBTL) can significantly reduce stoving temperature without reducing storage stability.
Can you provide technical documentation and bulk pricing?
Yes, technical data sheets and SDS documentation are available on request, and our team can provide bulk pricing and lead times based on your target volume and delivery location.
Get a Quote for Desmodur BL 3175 SN
Contact our team for a quote, technical data sheet, or SDS for Desmodur BL 3175 SN. We support bulk supply and global shipping for industrial finishers and automotive coating manufacturers.
