Reversacol photochromic dyes find many applications in plastics, films, coatings and inks as colour-enhancing effects or functional UV-indicators. The widest area of application is in prescription photochromic lenses where dyes can be incorporated in-mass or as a surface coating onto the lens.
Reversacol dyes are typically incorporated ‘in-mass’ within the matrix of an optical monomer, usually a methyl methacrylate resin blend, and then thermally or UV-cured. Photochromics can also be incorporated into a sandwich layer of a lens or a coating via dipping or spin coating. Such methods allow manufacture of photochromic lenses if very rigid plastic is required for the application.
Applications for Reversacol photochromic dyes in plastics include; Toys, Novelties, Packaging, Security Markers, Films/Laminates, Clothes and Cosmetics such as Nail Varnish.
Reversacol Dyes are readily incorporated into plastics extrusion processes due to their high temperature resistance. The flexural modulus of the matrix is an important consideration for the dye performance. Softer, low flexural modulus polymers such as LDPE, HDPE and polypropylene are all excellent media for exhibiting Reversacol photochromic dye activation. Engineering plastics such as polycarbonate, polymethyl methacrylate, PET, styrenes and ABS, tend to have higher flexural modulus which can lead to reduced photochromic response; the matrix can be physically too stiff to allow the photochromic molecules to twist into their fully activated forms.
Inks and Coatings
Reversacol Photochromic dyes can be incorporated into solvent-based ink and overprint varnishes as well as coating systems for use in gravure and flexo printing, screen print for T-shirts, and nail varnish.
As part of a covert or overt security marking or brand-protection system, Reversacol Photochromic dyes can allow a colour change effect when irradiated by a specific wavelength UV.