Desmodur-HDI based curing agent

Covestro Desmodur N3800 HDI polyisocyanate curing agent increases flexibility

type	Aliphatic polyisocyanate (elastomeric HDI trimer)
form of supply	Solvent free
Solvent free	Curing agent components for lightfast polyurethane coating systems

Specification

characteristic	Numerical value	Units of measurement	method
NCO content	11.0 ± 0.5	%	DIN EN ISO 11909
Viscosity, 23°C	6,000 ± 1,200	mPa·s	DIN ENISO 3219/A.3
Color value (Hazen)	≤80		DIN EN 1557
HDI monomer	≤0.30	%	DIN EN ISO 10283

Other data*

characteristic	Numerical value	Units of measurement	method
Viscosity, 25°C	about 5500	mPa·s	DIN EN ISO 3219/A.3
equivalent	about 382
Flash point	about 235	°C	DIN 22 719
Density@20°C	about 1.12	g/ml	DIN EN ISO 2811

*This data is general information and is not part of the product specification.

Solubility / dilution
Typically, Dosmodur® N3800 can be used with solvents such as esters, ketones and aromatic hydrocarbons such as ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, 100# naphtha solvent and its mixture for dilution. The product is generally miscible with the above solvents, but the stability of the diluted solution should still be tested first. Urethane grade solvent should be used (water content is less than 0.05%, and the solvent cannot contain hydroxyl, amino and other reactive groups that react with the product). This product cannot be diluted to less than 40% solids. Long-term storage of low solids bases may cause cloudiness and precipitation.

compatibility
Dosmodur® N3800 can be mixed with the following products: aliphatic polyisocyanates such as Desmodur® N100, N75, N3200, N3400, N3600 and Desmodur® Z4470; aromatic polyisocyanates such as Desmodur® L, HL and IL; polyhydroxy polyesters such as Desmophen® 670; polyacrylates such as Desmophen® A series. Compatibility must be tested before use. However, Desmodur® N3800 cannot be mixed with branched polyhydroxy polyesters such as Desmophen® 651 and polyhydroxy polyethers such as Desmophen® 1380BT.

Features/Applications
Dosmodur® N3800 is mainly used as a curing agent in lightfast two-component polyurethane coating systems with high weather and chemical resistance, excellent gloss retention and outstanding mechanical properties. Preferred co-reactants are polyacrylates or polyhydroxy polyesters. Coating systems based on Dosmodur® N3800 are mainly used in self-drying and force-drying automotive OEM, automotive refinish and transportation coatings as well as general industrial and plastic coatings.

store
This product is sensitive to moisture and should therefore be stored in its original airtight container. When properly stored at room temperature, this product has a shelf life of at least 6 months.

Safety: Hazard Identification
May cause an allergic reaction in contact with skin due to the presence of isocyanates. Product Safety Data Sheets, which contain labelling, shipping, storage and product disposal, product safety and ecological impact information, must be strictly followed.