| 摘要 |
In a first aspect, the invention provides an ink formulation comprising: (a) a near infrared absorbing system comprising a compound of the formula M1 W1.6O6, wherein M1 is one or more elements selected from the group consisting of H, He, alkali metals such as Li, Na, K, Rb, Cs, alkaline earth metals such as Be, Mg, Ca, Sr, Ba, rare-earth elements, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, AL Ga, in, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Hf, Os, Bi and I, or ammonium; (b) a colour change agent; and (c) a binder. The invention also provides alternative ink formulations for laser marking, a method of forming an image using the ink formulations and a substrate coated with the ink formulation of the invention. Ink formulations according to the invention have been found to have good laser imaging efficacy, and an essentially negligible impact on the background colour of the coating. |
