Before working with this product, you must read and become familiar with the available information on its risks, proper use, and handling. Information is available in several forms, e.g., in particular in the currently valid safety data sheets and product labels. For further information contact your Covestro representative.
Product description
Branched hydroxyl-bearing polyester.As a co-reactant for Desmodur® N/ultra N in the formulation of two-component polyurethane coatings with good gloss retention, lightfastness and chalking resistance.Also in combination with Desmodur® L/ultra L and HL in the formulation of fast-drying two-component coatings.
Applications
Desmophen® 680 BA is a hard co-reactant for use with Desmodur® N/ultra N. The drying properties of this combination are comparable with those of the acrylic resin/Desmodur® N/ultra N systems developed specially for automotive repair paints. It is therefore particularly suitable for the formulation of air-drying automotive and industrial coatings. Coatings crosslinked with Desmodur® L/ultra L and HL are particularly fast-drying, making them suitable for applications such as paper finishing.Desmophen® 680 BA/Desmodur® N/ultra N combinations can be formulated with and without the use of catalysts. Non-catalysed formulations are tack-free after approx. 4 hours at room temperature. They can be overcoated after 16 hours and are resistant to premium-grade petrol after 3 days. Overcrosslinking slows drying to the tack-free stage but improves solvent resistance. The cured paint films are hard but flexible, high-gloss and high-bodied and have good weather stability and lightfastness.
Form supplied
approx. 70 % in butyl acetate
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Hazen color value | ≤ 200 | DIN EN 1557 | ||
| Acid value | 16 ± 3 | mg KOH/g | DIN EN ISO 2114 | |
| Viscosity at 23°C | 3,000 ± 500 | mPa*s | DIN EN ISO 3219/A.3 | |
| Non-volatile content | 2 g resin/2 ml toluene/ 1 h 125 °C, convection oven | 70 ± 1 | % | DIN EN ISO 3251 |
| Hydroxyl content | 2,2 ± 0,5 | % | DIN EN ISO 4629-2 | |
| Water content | ≤ 0,1 | % | DIN 51 777/1 |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Equivalent weight | approx. 770 | |||
| Density at 20°C | approx. 1,08 | g/ml | DIN EN ISO 2811-2 | |
| Flash point | approx. 32 | °C | DIN EN ISO 2719 | |
| Alternative raw material share | 1) bio-based | approx. 15 | wt.-% | calculated |
| Alternative carbon share | 1) bio-based | approx. 18 | % | calculated |
Solubility / thinnability
Desmophen® 680 BA can be thinned with esters, ketones and aromatic hydrocarbons such as ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 1-methoxypropylacetate-2, toluene, xylene, solvent naphtha® 100 and mixtures thereof. However, the solutions formed must be tested for their storage stability.Aliphatic hydrocarbons cannot be used as solvents.Only PU grade solvents should be used (< 0.05 % water, free from other reactive impurities).Desmophen® 680 BA should not be thinned to below a solids content of 30 %. Solutions with a lower binder content in some solvents may result in turbidity.
Compatibility
Generally speaking, Desmophen® 680 BA is miscible with the Desmodur® and Desmophen® grades listed. However, the combinations must be tested for their compatibility. Desmophen® 680 BA can be mixed with Desmodur® L/ultra L, HL, N/ultra N and Z 4470, with polyester-based Desmophen® grades such as Desmophen® 670, 690 and 881 X. It is incompatible with Desmophen® 650. Compatibility with Acrylic resins has to be checked.
Storage
- Storage in original sealed Covestro container. - Recommended storage temperature: max. 30 °C. - Protect from moisture, heat and foreign material.
Storage time
Covestro represents that, for a period of six months following the day of shipment as stated in the respective transport documents, the product will meet the specifications or values set forth in section "specifications or characteristic data" above, what ever is applicable, provided that the product is stored in full compliance with the storage conditions set forth in and referenced under section "storage" above and is otherwise handled appropriately.The lapse of the six months period does not necessarily mean that the product no longer meets specifications or the set values. However, prior to using said product, Covestro recommends to test such a product if it still meets the specifications or the set values. Covestro does not make any representation regarding the product after the lapse of the six months period and Covestro shall not be responsible or liable in any way for the product failing to meet specifications or the set values after the lapse of the six months period.
Health and Safety Information
Disclaimer
General
The manner in which you use our products, technical assistance and information (whether verbal, written or by way of production evaluations), including any suggested formulations and recommendations, are beyond our control. Therefore, it is imperative that you test our products to determine suitability for your processing and intended uses. Your analysis must at least include testing to determine suitability from a technical, health, safety, and environmental and regulatory standpoint. Such testing has not necessarily been done by Covestro, and Covestro has not obtained any approvals or licenses for a particular use or application of the product.
Unless we otherwise agree in writing, all products are sold strictly pursuant to the terms of our standard conditions of sale which are available upon request.
All information and including technical assistance is given without warranty or guarantee and is subject to change without notice. It is expressly understood and agreed by you that you assume and hereby expressly release indemnify us and hold us harmless from all liability, in tort, contract or otherwise, incurred in connection with the use of our products, technical assistance, and information. Any statement or recommendation not contained herein is unauthorized and shall not bind us. Nothing herein shall be construed as a recommendation to use any product in conflict with any claim of any patent relative to any material or its use. No license is implied or in fact granted under the claims of any patent.
Non Medical and non Food Contact
This product is not designated for the manufacture of a medical device or of intermediate products for medical devices (1). This product is also not designated for other specifically regulated applications (e.g. including cosmetics, plant protection, fertilisers, plant strengtheners, food processing, food contact and others). If the intended use of the product is for the manufacture of a medical device or of intermediate products for medical devices or for other specifically regulated applications Covestro must be contacted in advance to provide its agreement to sell such product for such purpose. Nonetheless, any determination as to whether a product is appropriate for use in a medical device or intermediate products for medical devices, for Food Contact products or cosmetic applications must be made solely by the purchaser of the product without relying upon any representations by Covestro.
1) Please see the Guidance on Use of Covestro Products in a Medical Application document.
Sample
Any samples provided by Covestro are for testing purposes only and not for commercial use.
Typical value
These values are typical values only. Unless explicitly agreed in written form, they do not constitute a binding material specification or warranted values
Contact
Please use our contact form or contact us directly by sending an e-mail to technical-datasheets@cx.covestro.com .
