Name: Blocked Isocyanate for Powder Coatings BIP-80
Brand: Coatingsink
SKU: blocked-isocyanate-powder-bip
Availability: InStock

Question 1

How do I calculate the stoichiometric loading of BIP-80 against a hydroxyl-functional polyester resin?

Accepted Answer

BIP-80 has an NCO equivalent weight of 323 g/mol. Determine the OH equivalent weight of your polyester from its OH value (OH EW = 56,100 ÷ OH value in mg KOH/g). Then: crosslinker mass = (resin mass ÷ OH EW) × 323. In practice, target a slight NCO excess of 1.02–1.05 NCO:OH to ensure full conversion and optimal film properties.

Question 2

What byproduct does caprolactam blocking release during cure, and what precautions are needed?

Accepted Answer

At 160°C, caprolactam is cleaved from the HDI isocyanurate, liberating free NCO groups that react with polyester hydroxyls to form urethane linkages. Caprolactam volatilizes during the bake cycle; ensure adequate oven exhaust ventilation. Residual caprolactam can reduce adhesion on certain plastic substrates — run adhesion cross-cut tests when coating PP or PA.

Question 3

Can BIP-80 be co-crosslinked with HAA or TGIC in a hybrid powder system?

Accepted Answer

Yes. Blending BIP-80 with hydroxyalkylamide (HAA) is feasible for systems requiring very low-temperature cure flexibility or improved overbake resistance. Recalculate stoichiometry for the combined crosslinker NCO equivalents against total resin OH. Avoid blending with TGIC in outdoor-durable formulations, as TGIC's lower UV stability offsets the durability advantage of the HDI-based component.

NCO Content	13%
Melting Point	80–90°C
Recommended Dosage	25–35% on resin weight
NCO Equivalent Weight	323 g/mol
Deblocking Temperature	160°C

Blocked Isocyanate for Powder Coatings BIP-80

Specifications

FAQ

Interested in Blocked Isocyanate for Powder Coatings BIP-80?