METHOD FOR MEASURING RESIDUAL RADIATION-CURABLE MONOMERS OR OLIGOMERS

摘要

A method of measuring intensity of radiant energy fluoresced by a fluorescer in a radiation-cured coating. The method comprising the steps of: a) providing a coating (4) comprising: i) a radiation-curable monomer or oligomer; and ii) a fluorescer having an excitation energy at a wavelength lambda 2, the fluorescer fluorescing radiant energy of a wavelength lambda 3; b) curing the coating by exposure to radiant energy (14), thereby changing the intensity of radiant energy that would be fluoresced by the fluorescer if exposed to wavelength lambda 2; c) illuminating the radiation-cured coating with excitation energy (16) of a wavelength lambda 2, wherein at least 50 % of the excitation energy is absorbed by the upper 75 mu m of radiation-cured coating; and d) measuring the intensity (18) of the radiant energy fluoresced by the fluorescer at wavelength lambda 3. The above method can be used to measure the amount of residual radiation-curable monomer or oligomer present in a radiation-cured coating. This method of measuring residual monomer is especially useful where the intensity of the radiant energy fluoresced by the fluorescer at wavelength lambda 3 changes with the concentration of unreacted radiation-curable monomer or oligomer in the radiation-cured coating.