Molecular sieves powders are widely utilized in coating, paint and adhesive applications such as polyurethane formulations or metal rich paints. Molecular sieve 3A and 5A powders can adsorb over 20% by weight water and are typically used as 1 to 5% of the formulation.

Moisture will react with isocyanates in polyurethane-based coatings, sealants, adhesives or other elastomers. This can cause product deformities due to curing, CO2 off-gassing, bubbling, and degradation of other physical properties.

In one component polyurethane systems, cross-linking of the isocyanates occurs through the reaction with moisture from the surrounding atmosphere. Moisture within the polyurethane can initiate the hardening reaction prematurely and must be removed with molecular sieves.

In metallic pigment paints that are used for anti-corrosion and marine applications, moisture will react with the metals, generating hydrogen which can lead to off-gassing in product containers. In addition, sometimes the zinc and aluminum based paints contain chlorinated rubber compounds. In this case, moisture will cause gelling and shortened shelf life. Zn + 2 H20 -> Zn (OH)2 + H2 2 Al + 6 H20 -> 2 AI (OH)3 + H2