Desmodur-HDI based curing agent

Covestro Desmodur BL3370 MPA low temperature blocking hardener

type	Blocked polyisocyanates based on hexamethylene diisocyanate
form of supply	About 70% in 1-propylene glycol methyl ether acetate-2 (MPA)
use	Mixed with Desmophen® grades to prepare one-component stoving polyurethane coatings with high thermal yellowing resistance and light fastness; as an additive to traditional stoving coatings to improve their reactivity, flexibility and adhesion

Specification

characteristic	Numerical value	Units of measurement	method
Non-volatile component content (1g/60min/80°C)	70±3	%	DIN EN ISO 3251
Viscosity, 23°C	38500 ± 1200	mPa·s	DIN EN ISO 3219/A.3
Color value (Hazen)	≤ 60		DIN EN 1557

Other data*

characteristic	Numerical value	Units of measurement	method
Blocked NCO content	About 8.9%
Viscosity, 25°C	about 3200	mPa·s	DIN EN ISO 3219/A.3
equivalent	about 470
Flash point	about 49	°C	DIN 53 213/1
density	about 1.08	g/cm3	DIN EN ISO 2811

characteristic	Numerical value	Units of measurement	method
Blocked NCO content	About 8.9%
Viscosity, 25°C	about 3200	mPa·s	DIN EN ISO 3219/A.3
equivalent	about 470
Flash point	about 49	°C	DIN 53 213/1
density	about 1.08	g/cm3	DIN EN ISO 2811

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

Solubility / Dilution
Desmodur® BL3370 MPA can be used with esters, ketones and aromatic hydrocarbons such as ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, solvents Naphtha 100, 150, 200S and mixtures of these solvents. But still need to test the stability of the solution. Aliphatic hydrocarbons are not suitable as solvents. Desmodur® BL3370MPA cannot be diluted below 40% solids. Long-term storage of low solids solutions may cause turbidity and precipitation.

compatibility
Desmodur® BL 3370MPA is compatible with the following products in equivalent equivalent crosslinking reactions: Desmophen® 651, 670, 680, 690, 800, 1100, 1300, RD181, A160, A365, A450 and Desmophen® T1665. Always check the compatibility of the mixture.

Features/Applications
Desmodur® BL3370 MPA is mixed with polyol to prepare lightfast one-component polyurethane stoving paint. This product is mainly used in high-grade industrial topcoats (can coatings/coil coatings) and automotive OEM primers. Desmodur® BL3370 MPA can also be used as an additive to traditional baking systems to enhance flexibility and adhesion.
Typical bake conditions are as follows:

100°C for 50 minutes
or 120°C for 20 minutes
or 160°C for 7 minutes

Yellowing may occur above 160°C, depending on the co-reactants used and the bake time. In the use of coil coatings, sufficient crosslinking is achieved at a maximum board temperature (PMT) of approximately 216°C. It is not necessary to add catalyst to Desmodur® BL3370 MPA.

store
Desmodur® BL3370 MPA should be stored in airtight containers. When stored properly at room temperature, this product has a shelf life of at least 6 months.

Safety: Hazard Identification
Flammable and eye irritating, product safety data sheet (300202) should be strictly followed. It includes information on labelling, transportation and storage, as well as information on product use, product safety and ecology.