Multilayer Photocurable Films
Original Publication Date: 1985-Mar-01
Included in the Prior Art Database: 2005-Feb-18
In using photocurable films, the amount of light absorption of a particular wavelength or range of wavelengths can be controlled by controlling the composition of the film. The composition is controlled by making a multilayer photocurable film where the nature and concentration of the photoactive species is chosen to give the desired optical properties. For example, to increase light absorption at the bottom 10 microns of a 50-micron solid film, cast a 10-micron film with a high optical density at the desired wavelength and then cast a top 40-micron film of lower optical density. The optical densities are controlled either by varying the concentration of the photoactive species and/or by using at least two different photoactive species with different absorption properties at the wavelengths of interest.