Aqueous hydroxyfunctional polyacrylic dispersion.Waterborne 2K-Polyurethane varnishes in combination with aliphatic Polyisocyanates.
Product description
Applications
Bayhydrol® A 2470 is a hydroxyfunctional polyacrylic dispersion which can be thinned with water to application viscosity. The viscosity of the product is largely governed by the pH. As the pH may decrease during storage, a decrease in viscosity is also to be expected. The viscosity can be restored to its original value by the addition of small amounts of an aqueous 10 % solution of dimethyl ethanol amine.Bayhydrol® A 2470 combined with aliphatic polyisocyanates yields high-gloss top coats which can be dried at room temperature or force-dried, e.g. at 80 °C.The cured paint films are hard and flexible with outstanding resistance to solvents and water and excellent weatherability.Application of a clearcoat based on Bayhydrol® A 2470 directly on wood may lead to discoloration.When properly formulated, e.g. in combination with Bayhydur® ultra 304 in an NCO / OH ratio of 1.5 : 1, the pot life is approx. 4 hours.Bayhydrol® A 2470 has good pigment wetting properties and high shear stability. Bead mills have proved suitable as grinding equipment. Only pigments and extenders with a minimum water-soluble content should be used. Given the many pigments and extenders available, compatibility testing should always be carried out.When mixing Bayhydur or Desmodur into the mill base, a thickener must be added to ensure a high shear effect.The addition of approximately 0.4 % Borchi®Gel PW 25 (calculated on the solid binder) has proved suitable for formulations based on Bayhydrol® A 2470.Application and formulation equipment can be cleaned with water, alkaline cleaning agents or isopropanol.
Form supplied
Approx. 45% in water / SN 100 / 1-butoxy-2-propanol, triethanol amine / dimethyl ethanol amine neutralized, 4% SN 100, 4% 1-butoxy-2-propanol.
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Viscosity | at 23 °C, D = approx. 40 s^-1 | 1,500 - 3,000 | mPa*s | DIN EN ISO 3219/A.3 |
| Non-volatile content | (1 g/1 h/125 °C/convection oven) | 44 - 47 | % | DIN EN ISO 3251 |
| pH-value | 7 - 8 | DIN ISO 976 |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| OH % on solid | approx. 3,9 | % | calculated | |
| Acid value | approx. 10 | mg KOH/g | DIN EN ISO 2114 | |
| Density | at 20 °C | approx. 1,06 | g/ml | DIN EN ISO 2811 |
Solubility / thinnability
Bayhydrol® A 2470 can be thinned with water in any ratio.
Compatibility
Suitable co-reactants for the formulation of aqueous two-component polyurethane systems include Desmodur® N 3400, ultra N 3600 or ultra N 3900, Bayhydur® ultra 304, ultra 305, ultra 3100, ultra 2487/1 or ultra 2655.
Storage
- Storage in original sealed Covestro containers. - Recommended storage temperature: > 0 ≤ 30 °C. - Protect from frost, heat and foreign material. General information: Short-time cooling down to -18 °C does not typically damage the product, but the viscosity may increase significantly. Prolonged freezing can damage the product irreversibly. Prolonged storage at higher temperatures may result in a decrease of viscosity and/or an increase of average particle size, possibly resulting in sedimentation or coagulation. The viscosity of the product is largely governed by the pH. As the pH may decrease during storage, a decrease in viscosity is also to be expected. The viscosity can be adjusted to its original value by the addition of small amounts of an aqueous 10 % solution of dimethyl ethanol amine.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
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.
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 .
