Incozol EH for non-crystallising 1K Polyurethane coatings development

Incozol EH is a new non-crystallising urethane bis-oxazolidine latent hardener specifically developed for 1K polyurethane coating formulations.

• Flooring (pigmented and clear top-coats)
• Balconies
• General waterproofing

• Enhances cure speed of 1K PU systems without the need for additional metal catalyst
• Increases through-cure, hardness development, chemical resistance and ultimate tensile performance of 1K PU coatings
• Improves aesthetics and film integrity of PU systems by elimination of CO₂ gassing
• Has more acceptable odour compared to standard bis-oxazolidines

Product	Seeded (Y/N)	Storage Temp. (°C)	1 week	2 weeks	1 month	2 months	4 months	6 months
Incozol 4	N	-15	CRY	CRY	CRY	CRY	CRY	CRY
	Y		CRY	CRY	CRY	CRY	CRY	CRY
	N	20	PC	PC	CRY	CRY	CRY	CRY
	Y		PC	PC	CRY	CRY	CRY	CRY
Incozol EH	N	-15	NC	NC	NC	NC	NC	NC
	Y		NC	NC	NC	NC	NC	NC
	N	20	NC	NC	NC	NC	NC	NC
	Y		NC	NC	NC	NC	NC	NC

As can be seen in this table, Incozol EH shows excellent storage stability, with no signs of crystallisation even when seeded with a potential nucleation site (to mimic dirt contamination). This is in contrast to isobutyraldehyde based oxazolidines (e.g. Incozol 4), which provide limited storage stability at these temperatures.

Storage stability The change in viscosity was measured for unopened containers of PU prepolymer without Incozol (control), then with the addition of Incozol 4 and Incozol EH at a 1:1 stoichiometry based on the total % NCO of the flooring system. Oxazolidines demonstrate excellent storage stability even after storage at 40°C for 56 days.

Moisture triggered chemistry Using Incozol EH allows the material to use atmospheric moisture to trigger the curing process. This means the waterproof membranes are capable of curing in a wide range of conditions including extreme temperature ranges and humidity variations. Unlike traditional polyurethane systems they do not release CO2, which often causes gassing, and application is not delayed by adverse weather conditions.