Covestro Desmophen® 670 lightly branched hydroxyl polyester for flexible and weather-resistant formulations
|
type |
Lightly branched hydroxyl polyester |
|
form of supply |
Solvent free |
|
use |
As a co-reactant, typically combined with Desmodur® N75 and Desmodur® N3390 for elastic, weatherable coating formulations |
Specifications
|
characteristic |
Numerical value |
Units of measurement |
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*
|
characteristic |
Numerical value |
Units of measurement |
method |
|
equivalent |
about 395 |
|
|
|
Density@20℃ |
about 1.17 |
g/ml |
DIN EN ISO 2811-1 |
|
Flash point |
about 195 |
°C |
DIN EN ISO 2719 |
|
pour point |
about 8 |
°C |
DIN ISO 3016 |
*This data is general information and is not part of the product specification.
application
Desmophen® 670 is combined with Desmodur® N75 or N3390 to form a film, which has good low temperature elasticity and good weather resistance. They are mainly used to coat plastics and dry strongly, eg at 80°C, Desmophen® 670 can be used as a toughener for other DD coating systems.
compatibility
Desmophen® 670 mixes easily with polyester-based Desmophen and various ethylene copolymers. However, their combination must be tested for compatibility. It has only limited compatibility with acrylates based on Desmophen® grades and cellulose butyl acetate.
Solubility/Dilution
Desmophen® 670 is soluble in ethyl acetate, butyl acetate, 1-methoxy-2, methyl isobutyl ketone, toluene and mixtures thereof. However, the solution formed must be tested for its storage stability. Xylene solutions above 40% solids will separate in a short time. Only polyurethane grade solvents can be used (<0.05% water, reactive impurities in free form).
store
- Store in original Bayer MaterialScience sealed container.
- Recommended storage temperature: ≤30℃.
- Avoid 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 solvent. And can be further processed without loss of quality.
storage time
Provided that the product has been stored in full compliance with the requirements in the "Storage" clause above and handled properly, the product meets the specifications stated in the "Specifications or Characteristic Values" clause above for a period of 6 months from the date of shipment stated on the shipping document or characteristic value (as applicable). The fact that a product exceeds the 6-month period above does not mean that it no longer meets the specifications or the values set in the characteristic values. However, it is recommended that products older than 6 months from the date of shipment be tested prior to use to confirm that they still meet the values set in the specifications or characteristic values. The manufacturer makes no commitments for products older than 6 months from the date of shipment, and does not assume any responsibility or liability for non-conformance to specifications or set values in characteristic values.
