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
Hydrophilically modified, aliphatic polyisocyanate based on hexamethylene diisocyanate (HDI).As the hardener/binder component for high-quality waterborne polymer dispersions and as an additive to improve the property level of waterborne coating and adhesive systems.With respect to its composition, the product corresponds to the following sections of the U.S. FDA’s guidelines Title 21 CFR: Section 175.105 “Adhesives”.
Applications
Because of its hydrophilic character, Bayhydur® ultra 304 can be easily emulsified in the aqueous phase.It is used mainly as the crosslinking partner for waterborne polyol binders (Bayhydrol®) and as a crosslinker for largely pH-neutral waterborne polymer dispersions, including polyurethane (Dispercoll® U), polyvinyl acetate, polyacrylate and synthetic rubber dispersions.After addition of Bayhydur® ultra 304, the ready-to-use two-component formulation must be used within the pot life. This is not only governed by the polymer content but also by its other constituents (resin, thickener, plasticizer, etc.). Within many dispersions, the end of this pot life – usually several hours – is not marked by gelling.The addition of 3 – 10 % Bayhydur® ultra 304 is recommended to crosslink adhesive dispersions containing 40 – 60 % polymer. Effective mechanical stirring is required to emulsify Bayhydur® ultra 304 in adhesive dispersions. Manual stirring by hand is not sufficient to ensure good homogenization, especially in the case of low-viscosity adhesive dispersion. Inadequate dispersion may result in the formation of granular deposits in the adhesive.Should Bayhydur® ultra 304 be modified with an additive, this may contain no groups which react with isocyanate and no secondary components which may do so. In particular, any additives used must be free of secondary components which are alkaline or have a catalytic effect on isocyanate groups. Even at very low concentrations, these can cause an increase in viscosity or even solidification.
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| NCO content | 18,2 ± 0,5 | % | M105-ISO 11909 | |
| Viscosity | at 23 °C | 4,000 ± 1,500 | mPa*s | M014-ISO 3219/A.3 |
| Color value | (Hazen) | ≤ 60 | M017-EN 1557 | |
| Monomeric HDI | < 0,10 | M106-ISO 10283 |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Equivalent weight | approx. 230 | |||
| Density | approx. 1,16 | g/ml | DIN 51757 | |
| Flash point | 226 | °C | DIN EN 22719 |
Solubility / thinnability
Generally speaking, Bayhydur® ultra 304 has good compatibility with the solvents listed: esters, ether esters, xylene and solvent naphtha® 100. However, the solubility/compatibility should be tested in each individual case.Only PU grade solvents (< 0.05 % water) should be used.
Storage
- Storage in original sealed Covestro container. - Recommended storage temperature: 0 - 30 °C. - Protect from moisture, heat and foreign material. General information: Hydrophilic isocyanates are very moisture-sensitive and react with water to form carbon dioxide and insoluble ureas. The containers must always be kept tightly closed. The access of water in all forms (moist air, solvents, moist containers) must be prevented, because the generation of carbon dioxide can lead to dangerous increases in pressure. Storage at higher temperatures will result in increase of color and viscosity. Due to the raw materials, the product may show visible turbidity caused by the cold. This turbidity occurs at approx. + 5 °C and is reversible when heated to room temperature. The product properties are not affected.
Storage time
Covestro represents that, for a period of nine 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 nine 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 nine 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 nine 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 .
