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
Anionic, UV-curable polyurethane dispersion.Bayhydrol® UV 2689/2 is used in the formulation of industrial waterborne UV clear and pigmented coatings. Main applications are plastic coatings (e.g mobile phones) and wood coatings. Before UV curing the surface of dried films is soft and slightly tacky. After UV-cure the coatings are hard with high chemical and mechanical resistance. The product is suitable to achieve high gloss coatings.Bayhydrol® UV 2689/2 does not contain intentionally added organotin compounds.
Applications
Bayhydrol® UV 2689/2 is used for the formulation of waterborne UV coatings, in particular for plastic applications. The addition of 1.0 to 2.5 wt.-% photoinitiator relative to binder has proven effective for initiation.We achieved good results with Irgacure® 500, Irgacure® 127, Irgacure® 819 DW (Ciba) and Esacure® KIP 100F (Lamberti). Viscosity is set by the addition of polyurethane thickeners for clear coats or acrylic thickeners for metallic effect coatings.As the dispersion has a relatively high surface tension the formulation should always contain a wetting agent, e.g. BYK® 348 (BYK) to avoid surface defects. Matting agents and additives can be dispersed directly into the formulation using a dissolver. Bayhydrol® UV 2689/2 can be easily matted using common matting agents. The formulation of metallic effect coatings using suitable metallic pigments is also possible. The product can also be combined with Bayhydur® or other hardeners to formulate ”dual cure” waterborne UV coatings.After evaporation of the water and before UV-cure, the coatings are soft and slightly tacky. Water-free coatings can be cured with suitable UV-curing equipment at a line speed of typically 5 to 10 m/min per 80 W/cm lamp. To achieve the best film properties the coating temperature should be higher than 60 °C when entering the UV zone. Care has to be taken if temperature sensitive materials are cured in this way. During UV curing a further temperature increase of 20 to 60 °C is possible depending on conditions.UV curing yields surfaces with high hardness, very good mechanical strength and excellent chemical resistance especially against cosmetics.
Form supplied
Approx. 42 % solids dispersion in water
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Non-volatile content | (1 g/1 h/125 °C, convection oven) | 40,0 - 44,0 | % by wt. | DIN EN ISO 3251 |
| Viscosity | D = 40s^-1 | < 1,000 | mPa*s | DIN EN ISO 3219/A.3 |
| pH | 7,0 - 8,5 | DIN ISO 976 |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Pendulumn hardness | 190 | s | DIN 53157 (König) | |
| Pencil Hardness | > 1 H | DIN EN 13523-4 | ||
| Double rubs acetone (10) | Unchanged | |||
| Double rubs ethanol (50) | Unchanged | |||
| Double rubs petrol (50) | Unchanged |
Solubility / thinnability
Bayhydrol® UV 2689/2 can be thinned with water.
Compatibility
The dispersion should be formulated and applied at pH between 6.7 and 9.0. The stability of the product outside this pH range is very limited. In general, the product is compatible with many other dispersions, including UV-curing dispersions. However, compatibility must be tested in each case. Additions of solvent, which may be necessary as an additive, are generally unproblematic. Addition of UV monomers (i.e. low molecular weight acrylates) is possible for certain types of monomers but must be tested in each case as a negative influence on viscosity and storage stability is possible.
Storage
- Storage in original sealed Covestro container. - Recommended storage temperature: 5 - 30 °C. - Protect from frost, intense radiation (light, UV), heat and foreign material. General information: The product is sensitive to frost. Freezing will damage the product irreversibly. Prolonged storage at higher temperatures may result in an increase of average particle size, risk of sedimentation, risk of pH-drift and ultimately coagulation. Even though the product is stabilized by a biocide, contamination with certain bacteria, fungi or algae may render the product unusable.
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
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 .
