UV-Curable Coatings for Opaque Concrete Adherence

The patent changes the chemical parameters of the photoinitiator system by selecting photoinitiators with absorption maxima in the near-UV region (380-405 nm) that better match the transmission window of common pigments. This parameter adjustment allows the curing system to operate at wavelengths that penetrate through pigmented coatings more effectively, resolving the contradiction between achieving opacity and maintaining curing completeness.

The patent employs a composite photoinitiator system combining multiple photoinitiators with different absorption characteristics (e.g., Type I and Type II photoinitiators with complementary absorption spectra). This composite approach creates a synergistic effect where the combined system can initiate polymerization across a broader wavelength range, enabling effective curing through opaque, pigmented coatings that would otherwise block single-wavelength UV sources.

The patent incorporates silane coupling agents and adhesion promoters in the primer formulation that chemically react with the concrete substrate surface before the UV curing process. This preliminary chemical bonding creates a strong interface layer that prevents subsequent delamination, allowing the fast UV curing process to proceed without compromising adherence to the challenging concrete substrate.

The patent uses silane-based adhesion promoters as intermediary substances between the UV-curable coating and the concrete substrate. These intermediaries form chemical bridges: one end bonds to the concrete surface through silane hydrolysis and condensation, while the other end is compatible with the UV-curable resin matrix. This intermediary layer resolves the contradiction by enabling both fast UV curing and strong substrate adherence.

The patent transitions from relying solely on UV light penetration through the coating thickness to a multi-dimensional curing approach. This includes using photoinitiators with long-wavelength absorption that penetrate deeper, combining Type I and Type II photoinitiator mechanisms that operate synergistically, and potentially incorporating thermal or chemical curing components that activate through different physical principles, enabling complete curing of thick coating layers.

The patent adjusts the photoinitiator concentration and type to optimize curing of thick sections. By selecting photoinitiators with appropriate half-lives and quantum efficiencies for deep penetration, and adjusting their concentrations to ensure sufficient radical generation throughout the coating thickness, the system achieves complete curing even in thick, pigmented, or multi-layer coatings applied at site.