Polymerization method using ultraviolet light

A method for the free-radical polymerization of a polymerizable material by irradiation of said material with ultraviolet light at a temperature between 0.degree. C. and 100.degree. C. according to a predetermined program, which method comprises, as the first step in said program, initiating polymerization of said polymerizable material in an initiation phase by irradiating said material with ultraviolet light having a wavelength between 320 nanometers and 400 nanometers in the presence of a free-radical photoinitiator, and then, as a further step in said program, controlling the further course of the polymerization in a polymerization phase by increasing the intensity of said ultraviolet light with time during said polymerization phase, relative to the intensity of said light at the onset of said polymerization phase, said polymerizable material comprising a major amount of at least one monomer which does not absorb ultraviolet light of the aforementioned wavelength and, distributed homogeneously therethrough, an ultraviolet absorber which does absorb ultraviolet light of the aforementioned wavelength but which is inert, or only weakly effective, as a free-radical photoinitiator.