摘要 |
<p>A laser-markable composition comprises a marking component and an organic compound, wherein the organic compound absorbs laser radiation at 780 to 2000 nm and thereby causes the marking component to change color, and wherein the organic compound has an absorptivity ratio, A r, of at least 1.25, wherein the absorptivity ratio is defined as formula (I): wherein: Ap780-2000 nm is an absorbance peak in the wavelength region of 780 to 2000 nm; and Aave600-700 nm is the average absorbance in the wavelength region of 400 to 700 nm. A y = A p 780 - 2000 nm A ave 400 - 700 nm ( I )</p> |