Covestro Desmodur BL 3175 SN Heat-activated HDI-based curing agent for one-component polyurethane coatings

Product Specifications

*The above values ​​are general information and are not part of the product specification.

Solubility/Dilution
Desmodur® BL 3175 SN generally has good miscibility with the following solvents, but the storage stability of the prepared solution must be tested. Desmodur® BL 3175 SN can be diluted with solvents of ketones, esters, ether esters and aromatics to a solution with a solid content of 40% by weight. Dilute it to a 60% solid solution (by weight) with a high-boiling aromatic hydrocarbon solvent, such as a mixture of 100# and 150# solvent naphtha.
Aliphatic hydrocarbon solvents should not be used.

Compatibility
When given an equivalent ratio (NCO/OH=1.0), Desmodur® BL 3175 SN is generally compatible with Desmophen® 651, 670, 680, 690, RD 181, A 160, A 265, A 365, A 450 and A 565 and Desmophen T 1665 are miscible. It can also be used with various plasticizers, such as phosphoric acid, sulfonic acid, adipic acid and phthalates. However, the miscibility of the resulting mixture must be tested.

Features/Applications
Desmodur® BL 3175 SN can be used as curing agent in color retention and weather resistance one-component polyurethane coatings. Adding a catalyst, such as dibutyltin dilaurate (DBTL), can significantly reduce the baking temperature without affecting the storage stability. This product can be used in high-quality industrial decorative paints (electrical appliances, small components, can coatings, coil coatings, etc.) as well as primer surfacers and topcoats in automotive decorative paints. Desmodur® BL 3175 can also be used as an additive in traditional baking systems to improve the flexibility and adhesion of the paint film. When Desmodur® BL 3175 is mixed with Desmophen® 651, the possible baking cycle is:
No catalyst 160℃ 60 minutes
180°C 15 minutes
200°C 7 minutes
With catalyst 130℃ for 60 minutes
150°C 15 minutes
175°C 7 minutes
Depending on the co-reactants used and the baking time, the paint film may turn yellow when the temperature is above 160°C. When Desmodur® BL 3175 is used in coil coating systems, it can be fully crosslinked without the addition of catalyst DBTL at a maximum panel temperature of about 241°C and above. If adding 1% DBTL (calculated on the basis of resin solids), the same effect can be obtained at the highest plate temperature of about 224°C.

Safety: Hazard Identification
It is flammable, may be irritating to skin and mucous membranes, and may cause allergies, so it must be used with extreme care. Harmful to aquatic life, may cause long-term adverse effects in the aquatic environment.
Vapors may cause drowsiness, dizziness.
The Safety Data Sheet (028952) must be strictly followed. It includes relevant information such as labeling, transportation and storage, as well as relevant information on product use, product safety and ecology.

�To improve the flexibility and adhesion of the paint film When Desmodur® BL 3175 is mixed with Desmophen® 651, the possible baking cycle is:
No catalyst 160℃ 60 minutes
180°C 15 minutes
200°C 7 minutes
With catalyst 130℃ for 60 minutes
150°C 15 minutes
175°C 7 minutes
Depending on the co-reactants used and the baking time, the paint film may turn yellow when the temperature is above 160°C. When Desmodur® BL 3175 is used in coil coating systems, it can be fully crosslinked without the addition of catalyst DBTL at a maximum panel temperature of about 241°C and above. If adding 1% DBTL (calculated on the basis of resin solids), the same effect can be obtained at the highest plate temperature of about 224°C.

Safety: Hazard Identification
It is flammable, may be irritating to skin and mucous membranes, and may cause allergies, so it must be used with extreme care. Harmful to aquatic life, may cause long-term adverse effects in the aquatic environment.
Vapors may cause drowsiness, dizziness.
The Safety Data Sheet (028952) must be strictly followed. It includes relevant information such as labeling, transportation and storage, as well as relevant information on product use, product safety and ecology.