VISIOMER® HEMA-P for Superior Adhesion to Polar Surfaces

VISIOMER® HEMA-P products serve as functional co-monomers in adhesives and coatings to facilitating enhanced adhesion to polar surfaces such as minerals, glass, and metals. When used in emulsion coatings, the addition of VISIOMER® HEMA-P boosts the adhesion of emulsion-based films on metal substrates, elevating the performance rating from GT5 to GT1, as shown in Figure 1.

Figure 1: Cross-cut test for emulsion coatings on metal substrates with and without the addition of 5 wt% VISIOMER® HEMA-P.

VISIOMER® HEMA-P is a specialty methacrylate that significantly enhances adhesion, even at low concentrations of 0.5 wt%. It combines high polarity with adequate flexibility, providing added value for new resin formulations.

Corrosion protection has always been acritical requirement for coatings, particularly as the industry shifts toward waterborne systems, which present challenges for maintaining anti–corrosion properties.

Research on acrylic emulsions incorporating 5 wt% of VISIOMER® HEMA-P demonstrate a notable enhancement in corrosion resistance compared to resins without any anti-corrosion agents (Figure 2). Panels coated with emulsion polymers containing VISIOMER® HEMA-P demonstrated impressive durability, withstanding corrosion for up to 168 hours during a saltwater immersion test.

Figure 2: Salt-spray test on galvanized steel substrate for emulsion coatings containing 5 wt% of VISIOMER® HEMA-P compared to those without it.

2-Hydroxyethyl-Methacrylate-Phosphate (HEMA-P) is a well-known adhesion promoter used in various applications, including adhesives and coating resins. Evonik provides two variants of this product VISIOMER® HEMA-P 70M and VISIOMER® HEMA-P 100. A detailed comparison of these two products is available in Table 1.

Figure 3: Structure of the active ingredient in VISIOMER® HEMA-P.

Evonik’s Specialty Methacrylates team looks forward to supporting you in finding the best solution for your next challenge in polymer design. For more information about our VISIOMER® HEMA-P products, please get in touch.