Tungsten-based photochromic composite films were fabricated using peroxopolytungstic acid methanol solution and transparent urethane resin. The composite films showed photochromic properties by UV–vis light irradiation. Photochromic properties of the films were improved with addition of the other elements of Cu. The reaction rate constants k of the films with the Cu/W ratio of 0, 0.1, 0.5, and 1 were 2.68 × 10−2, 3.33 × 10−2, 2.57 × 10−2, and 1.51 × 10−2 min−1, and the constant of the film with Cu/W of 0.1 was larger than that of the nondoped film.

Mo-doped tungsten-based photochromic composite films were fabricated using a peroxoisopolytungstic acid methanol solution, peroxoisopolymolybdenum acid methanol solution, and transparent urethane resin. The non-doped composite films showed photochromic properties by UVVis light irradiation. The reaction rate constant was 2.68 © 10 ¹2 min ¹1 . The increasing Mo/W ratio in the film caused a blue shift of the absorption peak of the film. The reaction rate constants k of films with Mo/W rates of 0.1, 0.5, and 1.0 were 3.00, 4.23, and 3.53 © 10 ¹2 min ¹1. Those values were larger than that of a non-doped film. All composite films showed a reversible photochromic property, which was the coloring and bleaching property.

Tungsten-based photochromic composite films were fabricated using peroxoisopolytungstic acid aqueous solution and transparent urethane resin. UV–visible irradiation of the resulting composite films showed photochromic properties, indicating broad absorption with peaks at 650 and 900 nm. The coloring time was about 40 min. The colored composite films were transformed to clear film in a dark room in 90 h.