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
Desmodur Z 4470 SN/BA is an aliphatic polyisocyanate based on isophorone diisocyanate (IPDI) and dissolved Aromatic 100 and n-butyl acetate (2:1).
Applications
Desmodur Z 4470 SN/BA differs from conventional types of aliphatic polyisocyanates by having better solubility/dilutability in mild solvents (aromatics, aliphatics) as well as better compatibility with air-drying alkyd resins. Desmodur Z 4470 SN/BA polyisocyanate is mainly used as an “additive resin” in existing, ready-for-use coating formulations to accelerate their drying, curing, and chemical crosslinking to obtain shorter dry, tape, and recoat times, and improved hardness and gasoline resistance in cured films.When Desmodur Z 4470 SN/BA is used as an additional drying and curing component in air-drying alkyd coatings, NCO/OH ratios of less than 0.5/1.0 are usually sufficient. With some types of alkyd resins, higher additions of Desmodur Z 4470 SN/BA polyisocyanate will cause embrittlement. The best level of addition should be determined in each case.Weathering of films containing Desmodur Z 4470 SN/BA polyisocyanate is mostly dependent on the type of alkyd resin used. The slight yellowing of alkyd resins modified with unsaturated fatty acids is slightly increased by the polyisocyanate addition. This tendency to yellow is more pronounced at drying temperatures above 176°F (80°C). It is recommended that forced drying be carried out below 176°F (80°C).Combining Desmodur Z 4470 SN/BA polyisocyanate with flexible polyesters and acrylics or properly formulated polyester/acrylic blends yields two-component polyurethane coatings with outstanding weather resistance. Adding Desmodur Z 4470 SN/BA polyisocyanate limits the potlife of the coating material. The potlife is approximately 8 hours for coating materials adjusted to spray viscosity. The potlife is influenced by the ingredients used in the formulation of the coating. As with any product, use of Desmodur Z 4470 SN/BA polyisocyanate in a given application must be tested (including but not limited to field testing) in advance by the user to determine suitability.
Specification
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Non-volatile content | 70 ± 2 | % | ||
| NCO content | 11,9 ± 0,4 | % | ||
| Monomeric IPDI | < 0,35 | % | ||
| Hazen color value | ≤ 60 | |||
| Viscosity | at 25°C | 1,000 ± 300 | mPa∙s |
Typical Values
| Property | Test Condition | Value | Unit | Standard |
|---|---|---|---|---|
| Appearance | Clear, slightlyyellow liquid | |||
| Equivalent weight | avg. (as supplied) | 353 | ||
| Specific gravity | at 25°C | 1,04 | g/cm3 | |
| Weight per Gallon | at 25°C | 8,66 | lb. | |
| Flash point | (Setaflash) | 46 | °C | |
| Viscosity | at 23° C | 1,200 | mPa∙s |
Solubility / thinnability
Desmodur Z 4470 SN/BA polyisocyanate is completely soluble in, or reducible with, aromatic solvents, even in the absence of polar solvents such as esters, ketones, or ether esters. It is possible to formulate solutions with a minimum solids content of 20% that have good storage stability using aromatic solvents. Stability must be checked in the particular solvent mixture used. Aliphatic solvents should not be used for dilutions. However, Desmodur Z 4470 SN/BA polyisocyanate has enough compatibility with aliphatic solvents that it can be added to most aliphatic solvent-based coatings. Water-containing solvents and solvents such as alcohols should not be used. Desmodur Z 4470 SN/BA reacts with these materials, causing undesirable side effects.
Compatibility
Desmodur Z 4470 SN/BA polyisocyanate has good compatibility with Desmodur N and Desmodur L polyisocyanates. It can be combined with many alkyd resins, as well many Desmophen® polyesters and acrylics. Desmodur Z 4470 SN/BA is also compatible with vinyl copolymer resins and with some nitrocellulose and low molecular weight epoxy resins. Compatibility with cellulose acetate butyrate resins is limited.
Storage
Desmodur Z 4470 SN/BA stored in tightly sealed original containers and protected from heat, moisture, and foreign materials.
Storage time
Desmodur Z 4470 SN/BA has a shelf life of six months from date of receipt at customer, provided the material is stored in sealed original containers at the recommended storage temperature. The product is sensitive to moisture. Storage at higher temperatures will result in increase of color and viscosity. Storage at significant lower temperatures will result in solidification. This solidification is reversible by briefly heating the product without adversely affecting the quality of the product. Recommended storage temperature is 0 – 30 oC.
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 .
