Covestro certifies that the product meets specifications for 6 months from the date of shipment, provided it is stored and handled in accordance with the conditions specified in the ‘Storage’ section. After this period, product performance is not assured; Customers are responsible for retesting material before use. Covestro assumes no liability for product performance after 6 months.
Product description
Slightly branched, hydroxyl-bearing polyester.
Designed as a reactant, usually with Desmodur® N 75 and Desmodur® N 3390, for the formulation of flexible, weather-stable coatings.
Applications
Combinations of Desmophen® 670 with Desmodur® N 75 or N 3390 result in films with excellent low-temperature flexibility and very good weather stability. They are mainly used to coat plastics and are force-dried, e.g. at 80 °C. Desmophen® 670 can be used as a flexibilizer in other DD coating systems.
Form supplied
High viscosity resin
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Hydroxyl content | 3.9 - 4.7 | % | M023 - ISO 4629-2 | |
| Dynamic viscosity | 23 °C | 1,800 - 2,600 | mPa·s | M058 - ISO 3219 |
| Water content | ≤ 0.1 | % | M018 - DIN 51777-1 | |
| Acid value | 1 - 3 | mg KOH/g | M019 - ISO 2114 | |
| Color | Hazen | ≤ 150 | M017 - EN 1557 |
* Dynamic viscosity determined on an 80 wt.% solution in butyl acetate.
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Equivalent weight | 395 | g/mol | calculated based on OH content |
Solubility / thinnability
Desmophen® 670 is soluble in ethyl acetate, butyl acetate, 1-methoxypropylacetate-2, methylisobutyl ketone, toluene and mixtures thereof. However, the solutions formed must be tested for their storage stability.
Solutions in xylene with a solids content of less than 40 % will separate after a short time.
Only PU grade solvents should be used (< 0.05 % water, free from other reactive impurities).
Compatibility
Desmophen® 670 is miscible with a number of polyester-based Desmophen® grades and various vinyl copolymers. However, the combinations must be tested for their compatibility. It has only limited compatibility with acrylate-based Desmophen® grades and cellulose acetobutyrate.
Storage
- Storage in original sealed Covestro container.
- Recommended storage temperature: 0 - 30 °C
- Protect from moisture, heat and foreign material.
General information: Under certain conditions (temperatures below 15 °C, long storage) the product may become cloudy. It can be completely rehomogenized by heating to around 40 °C or adding solvent, and can be further processed without any loss of quality.
Storage time
Health and Safety Information
Before working with this product, you must read and become familiar with the available information regarding its risks, proper use, and safe handling. This information is provided in various formats, including the current Safety Data Sheet (SDS) and product label. SDS can be accessed via the following link:
Safety Data Sheets (SDS) for Covestro products | Covestro
For further questions, please use the contact information provided on this technical data sheet.
Disclaimer
Responsibility and Liability
The use of Covestro products, technical assistance, and information (regardless of how provided) is outside Covestro’s control and is solely the responsibility of the customer. The customer must conduct adequate testing to determine the suitability of products for its intended use, including but not limited to technical, health, safety, and environmental aspects. Unless otherwise agreed in writing, all products are sold exclusively under Covestro’s standard conditions of sale, which prevail in case of conflict and are available upon request.
The terms and conditions of sale and delivery are available via the following link:
https://order.covestro.com/covestrostorefront/saleConditions
All information is provided “as is” without warranties, express or implied, including merchantability or fitness for a particular purpose, and is subject to change without notice. To the maximum extent permitted by law, Covestro disclaims, and the customer assumes all liability for losses, damages, or claims arising out of use of Covestro products, technical assistance, or information. Any statement or recommendation not expressly contained in Covestro documentation is unauthorized and shall not bind Covestro. Nothing herein shall be construed as encouraging or recommending the use of any product in conflict with any claim of any patent. No license is implied or in fact granted under the claims of any patent.
Restrictions on Regulated Applications
This product is not intended for use in regulated applications such as agriculture, cosmetics, drinking water contact, medical products (e.g., medical devices), toys, or similar uses subject to specific regulatory requirements. Prior written approval from Covestro is required before this product may be used in any regulated application. The customer is solely responsible for ensuring compliance with all applicable laws and determining product suitability. Covestro disclaims all liability and warranties for unauthorized regulated uses.
Conditional Use in Regulated Applications
This product may be suitable for use in food contact. However, use in such applications requires prior written approval from Covestro. Legal requirements for such applications vary by country and jurisdiction, and the customer is solely responsible for verifying compliance with all applicable laws and regulations. Without Covestro’s written approval, the product may not be distributed or used for regulated purposes, and Covestro disclaims all liability for such use.
Typical Value
The values provided are typical only and do not represent binding specifications. Unless expressly confirmed in a written contract, these values are not part of the contractual quality agreement and must not be relied upon as a warranty or guarantee of product performance.
Sample
Samples provided by Covestro are intended solely for evaluation and testing purposes by the customer and may not be used in commercial applications, resold, transferred to third parties (except qualified testing service providers acting on behalf of the customer), reverse engineered, modified, or used in any manner not explicitly authorized in writing by Covestro. Samples are provided ‘as-is’ without any warranties, express or implied, including fitness for a particular purpose. Customers are solely responsible for ensuring safe handling, regulatory compliance, and suitability of the material for their intended evaluations. Covestro disclaims all liability for damages or losses arising from the use of samples.
Contact Information
Please use our contact form or contact us directly by sending an e-mail to technical-datasheets@cx.covestro.com .
