Stability in 1K aliphatic polyurethane systems

In 1K aliphatic coating systems Incozol EH is very effective in bringing enhanced performances such as: Storage stability in 1K PU balcony and flooring coating systems Low temperature storage stability - no crystallization effect

Storage stability in 1K PU balcony system In below graph both oxazolidine latent hardeners, Incozol 4 and Incozol EH were combined with an aliphatic polyether prepolymer without Incozol (control) at 1:1 stoichiometry based on % NCO of the prepolymer (approximately 8.5% w/w). Both oxazolidines show good in-can stability

Storage stability in 1K PU flooring system 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.

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.