Many waterborne polymers and dispersions have carboxyl functionality in their structure. These carboxyl groups are multifaceted in their utility. They are often necessary to introduce water solubility or water dispersibility characteristics to waterborne resins, impart stability to waterborne vehicles, and often offer advantages in dried film properties, especially with respect to substrate adhesion. However, due to the hydrophilic nature of these carboxyl groups, films from water-borne coatings often exhibit high water vapor permeability and poor wet adhesion properties. Attempts to overcome these deficiencies generally involve crosslinking the water-borne vehicles through these carboxyl groups. Crosslinking aqueous carboxylated polymers can impart or improve the following properties: (1) non-blocking characteristics; (2) chemical or detergent resistance; (3) film hardness; (4) water soak or humidity resistance; and (5) mar resistance.
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