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.
Product description
Desmophen 650A-65 PMA is a saturated polyester resin.
Applications
Desmophen 650A-65 PMA polyester is used as a coreactant for Desmodur N polyisocyanate two-component polyurethane coatings. Finishes based on Desmophen 650A-65 PMA polyester and Desmodur N polyisocyanates are well-suited for uses requiring light stability and weatherability as well as good chemical and abrasion resistance. Suitable substrates include metal, concrete, wood, plastics and paper. Adequate substrate preparation is advisable before using coatings containing Desmophen 650A-65 PMA polyester.The drying times of coatings based on Desmodur N polyisocyanate and Desmophen 650A-65 PMA polyester can be reduced by the addition of catalysts. Suitable catalysts include Desmorapid PP (0.2-0.5% based on solid resin) and dibutyl tin dilaurate (.003-.005% based on solid resin). Such additions reduce the potlife of the formulation and should be evaluated prior to use.The flow of systems containing Desmodur N polyisocyanate and Desmophen 650A-65 PMA polyester can be inmproved by additions of cellulose acetate butyrate resins such as CAB 381-0.1 (0.2% based on resin solids) or certain types of silicone fluids such as Baysilone Paint Additive OL-17 (0.05-0.2% based on resin solids). As with any product, use of Desmophen 650A-65 PMA in a given application must be tested (including but not limited to field testing) in advance by the user to determine suitability.
Form supplied
It is supplied in propylene glycol monomethyl ether acetate and xylene (6:1).
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Solids | 65 ± 3 | % | ||
| Water content | ≤ 0,1 | % | ||
| Viscosity | at 25°C | 10,000 - 20,000 | mPa∙s | |
| Acid number | ≤ 3,0 | |||
| Color | (Gardner) | ≤ 2,0 | ||
| Hydroxyl number | 155 - 190 |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Appearance | Light yellow liquid | |||
| Specific gravity | at 25°C | 1,14 | ||
| Equivalent weight | avg. (as supplied) | 325 | ||
| OH content | 5,2 | % | ||
| Flash point | (Setaflash) | 42 | °C | |
| Weight per Gallon | at 25°C | 9,5 | lb. |
Solubility / thinnability
Desmophen 650A-65 PMA polyester is soluble in esters such as ethyl acetate, in ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol, and in glycol ethers such as PM Acetate. Butyl acetate is unsuitable for use as the sole solvent. Desmophen 650A-65 PMA polyester is insoluble in aromatic and aliphatic hydrocarbons. However, it is possible to incorporate aromatic hydrocarbons such as tolune and xylene as diluents.
Compatibility
Desmophen 650A-65 PMA polyester is compatible with Desmodur® N 75A BA/X, N 100A, and N 3200A aliphatic polyisocyanates. It is incompatible with Desmodur N 3300A and 3390A BA/SN polyisocyanates, yielding hazy films and low gloss. Desmophen 650A-65 PMA polyester has only borderline compatibility with most polyester and acrylic resins. Desmophen R-221-75 polyester can be used at levels up to 10% of the Desmophen 650A-65 PMA resin solids as a pigment dispersing resin.
Storage
Desmophen 650A-65 PMA should be stored in tightly sealed containers and protected from moisture, heat, and foreign materials. The product is hygroscopic. Recommended storage temperature is at maximum 30°C.
Storage time
Desmophen 650A-65 PMA has a shelf life of six months after receipt of material by customer, provided the material is stored in sealed original containers.
Health and Safety Information
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, food 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.
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 .
