Desmodur-HDI based curing agent

Covestro Desmodur N3390 BA/SN HDI trimer curing agent Standard lightfast curing agent

type	Aliphatic polyisocyanate (hexamethylene diisocyanate trimer)
form of supply	About 90% butyl acetate/100 solvent naphtha (1:1) solution
use	Used as a curing agent combination for lightfast polyurethane coatings

Product Specifications

characteristic	Numerical value	Units of measurement	method
NCO content	19.6±0.3	%	DIN EN ISO 11909
Non-volatile components (2.2g/120min/100℃)	90±1	%	DIN EN ISO 3251
Viscosity@23℃	150	mPa.s	DIN EN ISO 3219/A.3
Color value	≤40		DIN EN 1557
HDI monomer content	<0.15	%	DIN 55 956

other data*

characteristic	Numerical value	Units of measurement	method
Viscosity@25℃	about 500	mPa.s	DIN EN ISO 3219/A.3
equivalent	about 214
Flash point	约50℃		DIN 53 213/1
Density@20℃	约1.13	g/ml	DIN EN ISO 2811

*The above values are general information and are not part of product specifications.

Solubility / dilution
Curing agent N3390 can be used esters, ketones, aromatic hydrocarbon solvents such as: ethyl acetate, butyl acetate, methoxy propyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, 100 #Solvent naphtha and its mixture dilution. Miscibility with the above solvents is generally good. However, the storage stability of the resulting solutions must be tested. Polyurethane grade solvents should be used (less than 0.05% water, no hydroxyl or amino reactive groups). Aliphatic hydrocarbons are not suitable solvents.
The curing agent N3390 should not be diluted below 40% solids. Solutions with low binder content may experience turbidity and precipitation in long-term storage.

compatibility
The curing agent N3390 is generally miscible with the following products. Namely: curing agent N100, N75, N3200, N3400, N3600 and curing agent Z4470 type aliphatic isocyanate; curing agent L, HL and IL type aromatic polyisocyanate; Desmophen 670 type polyester polyol; Desmophen A type polyacrylate. However, the compatibility of the prepared solution must be tested. Curing agent N 3390 is not compatible with branched polyester polyols such as Desmophen 651 or polyether polyols such as Desmophen 550U.

Features/Applications
The curing agent N3390 is mainly used as the curing agent component of the lightfast two-component polyurethane coating, which has excellent chemical resistance and weather resistance, outstanding gloss retention and excellent mechanical properties. Desirable co-reactants are polyacrylates or polyester polyols.
Coating systems formulated with curing agent N3390 are suitable for self-drying or baking, and are used for OEM, automotive refinish, transportation, industrial and plastic finishing.

store
Hardener N3390 is sensitive to moisture and should therefore be stored in its original airtight container. This product has a shelf life of at least 6 months if stored under proper conditions.

Safety
Flammable, skin contact may cause allergic reactions. Harmful to aquatic life, may cause long-term adverse effects in the aquatic environment. Contains isocyanates.