Covestro Bayhydur 304 water-based PU curing agent

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Product Specifications

*The above values ​​are general information and are not part of the product specification.

Solubility/Dilution
  Bayhydur 304 generally has good compatibility with the following solvents: such as esters, ether esters, xylene and solvent naphtha 100. However, the solubility/compatibility of the prepared solution must be tested. Use only polyurethane grade solvents (water content <0.05%).

Features/Apply
  Due to the hydrophilic nature of Bayhydur 304, it is easy to emulsify in aqueous media. Primarily used as a crosslinker for waterborne hydroxyl polyols (Bayhydrol®) but also for most pH-neutral aqueous polymer dispersions including polyurethane dispersions (Dispercoll® U), polyacetate Vinyl, polyacrylate and synthetic rubber dispersions. After adding Bayhydur 304, the prepared two-component system must be used up within the pot life. The pot life depends not only on the polymer content, but also on other components such as resins, thickeners, plasticizers, etc. In many dispersions, the pot life is usually several hours, but the end of the pot life cannot be judged by the gel. In polymer dispersions with a content of 40 – 60%, it is recommended to add 3-10% of Bayhydur 304 as a crosslinker with the binder dispersion. In order to emulsify Bayhydur 304 in binder dispersions, effective mechanical agitation is required. Manual stirring is not sufficient to ensure uniform emulsification, especially in low viscosity binder dispersions. Insufficient dispersion can lead to particle deposition in the adhesive.
If Bayhydur 304 needs to add modification additives, the additives cannot contain groups that react with isocyanates, nor can they contain secondary components that can react with isocyanates. It is especially worth noting that any additives added must not be basic or contain secondary components that catalyze isocyanate groups. Even low concentrations of these components can cause viscosity increases and even solidification.

Save
This product is sensitive to moisture and should be stored in the original sealed container at a temperature not exceeding 30°C. When stored under proper conditions, this product has a shelf life of at least 6 months. During storage, the viscosity will increase slightly.

Safety: Hazard Identification
  This product contains isocyanate, which can cause allergies in contact with the skin. The Safety Data Sheet should be read carefully. It includes relevant information such as labeling, transportation and storage, as well as relevant information on product use, product safety and ecology.