Covestro Desmophen® 670 Slightly branched hydroxylated polyester for flexible and weatherable formulations

Type	Slightly branched hydroxyl polyester
Form of Supply	Solvent free
Purpose	As a co-reactant, usually withDesmodur® N75andDesmodur® N3390combined for resilient, weather-resistant coating formulations

Specifications

Features	Value	Measurement unit	Method
Color value(Hazen)	≤150		DIN EN 1557
acid value	2±1	mgKOH/g	DIN EN ISO 2114
Viscosity@23°C ,80%% butyl acetate	2200±400	mPa·s	DIN EN ISO 3219/A.3
Hydroxyl content	4.3±0.4	%	DIN 53240/2
Water content	≤0.1	%	DIN 51777/1

Other data*

Features	Value	Measurement unit	Method
equivalent	about395
Density@20℃	about1.17	g/ml	DIN EN ISO 2811-1
Flashpoint	about195	°C	DIN EN ISO 2719
Pour point	about8	°C	DIN ISO 3016

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

Application
Desmophen® 670 is combined with Desmodur® N75 or N3390 to form a film, It has good low temperature elasticity and good weather resistance. They are mainly used for coating plastics and can be strongly dried, eg at 80°C, Desmophen® 670 can be used as a toughening agent for other DD coating systems.

Compatibility
Desmophen ® 670 is easy to mix with polyester based Desmophen and various ethylene copolymers. However, their combination must be tested for compatibility. Based on Desmophen® grades and cellulose butyl acetate it has only limited compatibility with acrylates.

Solubility/Dilution
Desmophen® 670 is soluble in ethyl acetate, butyl acetate, 1-methoxy-2, methyl isobutyl ketone, toluene and mixtures thereof. However, the solutions formed must be tested for storage stability. Xylene solutions above 40% solids will separate in a short time. Only polyurethane grade solvents may be used (<0.05% water, active impurities in free form).

Save
- Store in Bayer MaterialScience original airtight container.
- Recommended storage temperature: ≤30℃.
- Keep away from moisture, heat and foreign substances.

General information:Under certain conditions (temperature below 15°C, prolonged storage) the product may become cloudy. It can be completely homogenized by heating to about 40°C or adding solvents. and can be further processed without loss of quality.

Storage time
When the product is stored in full compliance with the requirements of the above "storage" clause and handled properly, the product meets the requirements within 6 months from the date of shipment stated on the transport document Specifications or characteristic values ​​described in the "Specification or characteristic values" clause above, as applicable. If the product exceeds the above-mentioned 6-month period, it does not mean that it no longer meets the set values ​​in the specifications or characteristic values. However, it is recommended that products older than 6 months from the date of shipment be tested before use to confirm that they still comply with the values ​​set in the specifications or characteristic values. The manufacturer does not make any promises for products that have been shipped more than 6 months from the date of shipment, and does not assume any responsibility and liability for non-compliance with specifications or set values ​​​​in the characteristic values.

The set value in ��. The manufacturer does not make any promises for products that have been shipped more than 6 months from the date of shipment, and does not assume any responsibility and liability for non-compliance with specifications or set values ​​​​in the characteristic values.